P\bPu\bur\brp\bpo\bos\bse\be o\bof\bf t\bth\bhi\bis\bs d\bdo\boc\bcu\bum\bme\ben\bnt\bt
-This document describes the qshape(1) program which helps the administrator
-understand the Postfix queue message distribution sorted by time and by sender
-or recipient domain. qshape(1) is bundled with the Postfix 2.1 source under the
-"auxiliary" directory.
-
-In order to understand the output of qshape(1), it useful to understand the
-various Postfix queues. To this end the role of each Postfix queue directory is
-described briefly in the "Background info: Postfix queue directories" section
-near the end of this document.
+This document is an introduction to Postfix queue congestion analysis. It
+explains how the qshape(1) program can help to track down the reason for queue
+congestion. qshape(1) is bundled with Postfix 2.1 and later source code, under
+the "auxiliary" directory. This document describes qshape(1) as bundled with
+Postfix 2.4.
This document covers the following topics:
* Example 2: Deferred queue full of dictionary attack bounces
* Example 3: Congestion in the active queue
* Example 4: High volume destination backlog
- * Background info: Postfix queue directories
+ * Postfix queue directories
o The "maildrop" queue
o The "hold" queue
10 and 20 minutes old, 1 between 320 and 640 minutes old and 12 older than
1280 minutes (1440 minutes in a day).
+When the output is a terminal intermediate results showing the top 20 domains
+(-n option) are displayed after every 1000 messages (-N option) and the final
+output also shows only the top 20 domains. This makes qshape useful even when
+the deferred queue is very large and it may otherwise take prohibitively long
+to read the entire deferred queue.
+
By default, qshape shows statistics for the union of both the incoming and
active queues which are the most relevant queues to look at when analyzing
performance.
One can request an alternate list of queues:
- $ qshape deferred | less
- $ qshape incoming active deferred | less
+ $ qshape deferred
+ $ qshape incoming active deferred
this will show the age distribution of the deferred queue or the union of the
incoming active and deferred queues.
The problem destinations or sender domains appear near the top left corner of
the output table. Remember that the active queue can accommodate up to 20000
-($qmgr_message_active_limit) messages. To check wether this limit has been
+($qmgr_message_active_limit) messages. To check whether this limit has been
reached, use:
- $ qshape -s active | head (show sender statistics)
+ $ qshape -s active (show sender statistics)
If the total sender count is below 20000 the active queue is not yet saturated,
any high volume sender domains show near the top of the output.
-The active queue is also limited to at most 20000 recipient addresses
-($qmgr_message_recipient_limit). To check for exhaustion of this limit use:
+With oqmgr(8) the active queue is also limited to at most 20000 recipient
+addresses ($qmgr_message_recipient_limit). To check for exhaustion of this
+limit use:
- $ qshape active | head (show recipient statistics)
+ $ qshape active (show recipient statistics)
Having found the high volume domains, it is often useful to search the logs for
recent messages pertaining to the domains in question.
nature of the errors. The destination will be retried again after the
expiration of a $minimal_backoff_time timer. If the error bursts are frequent
enough it may be that only a small quantity of email is delivered before the
-destination is again marked "dead".
+destination is again marked "dead". In some cases enabling static (not on
+demand) connection caching by listing the appropriate nexthop domain in a table
+included in "smtp_connection_cache_destinations" may help to reduce the error
+rate, because most messages will re-use existing connections.
The MTA that has been observed most frequently to exhibit such bursts of errors
is Microsoft Exchange, which refuses connections under load. Some proxy virus
the client as a "421" error.
Note that it is now possible to configure Postfix to exhibit similarly erratic
-behavior by misconfiguring the anvil(8) server (not included in Postfix 2.1.).
-Do not use anvil(8) for steady-state rate limiting, its purpose is DoS
-prevention and the rate limits set should be very generous!
+behavior by misconfiguring the anvil(8) service. Do not use anvil(8) for
+steady-state rate limiting, its purpose is (unintentional) DoS prevention and
+the rate limits set should be very generous!
-In the long run it is hoped that the Postfix dead host detection and
-concurrency control mechanism will be tuned to be more "noise" tolerant. If one
-finds oneself needing to deliver a high volume of mail to a destination that
-exhibits frequent brief bursts of errors, there is a subtle workaround.
+If one finds oneself needing to deliver a high volume of mail to a destination
+that exhibits frequent brief bursts of errors and connection caching does not
+solve the problem, there is a subtle workaround.
* In master.cf set up a dedicated clone of the "smtp" transport for the
destination in question.
number in the 10-20 range is typical).
* IMPORTANT!!! In main.cf configure a very large initial and destination
- concurrency limit for this transport (say 200).
+ concurrency limit for this transport (say 2000).
/etc/postfix/main.cf:
- initial_destination_concurrency = 200
- transportname_destination_concurrency_limit = 200
+ initial_destination_concurrency = 2000
+ transportname_destination_concurrency_limit = 2000
Where transportname is the name of the master.cf entry in question.
-The effect of this surprising configuration is that up to 200 consecutive
+The effect of this surprising configuration is that up to 2000 consecutive
errors are tolerated without marking the destination dead, while the total
concurrency remains reasonable (10-20 processes). This trick is only for a very
specialized situation: high volume delivery into a channel with multi-error
Hopefully a more elegant solution to these problems will be found in the
future.
-B\bBa\bac\bck\bkg\bgr\bro\bou\bun\bnd\bd i\bin\bnf\bfo\bo:\b: P\bPo\bos\bst\btf\bfi\bix\bx q\bqu\bue\beu\bue\be d\bdi\bir\bre\bec\bct\bto\bor\bri\bie\bes\bs
+P\bPo\bos\bst\btf\bfi\bix\bx q\bqu\bue\beu\bue\be d\bdi\bir\bre\bec\bct\bto\bor\bri\bie\bes\bs
The following sections describe Postfix queues: their purpose, what normal
behavior looks like, and how to diagnose abnormal behavior.
All mail that enters the main Postfix queue does so via the cleanup(8) service.
The cleanup service is responsible for envelope and header rewriting, header
-and body regular expression checks, automatic bcc recipient processing and
-guaranteed insertion of the message into the Postfix "incoming" queue.
+and body regular expression checks, automatic bcc recipient processing, milter
+content processing, and reliable insertion of the message into the Postfix
+"incoming" queue.
In the absence of excessive CPU consumption in cleanup(8) header or body
regular expression checks or other software consuming all available CPU
Congestion in this queue is indicative of an excessive local message submission
rate or perhaps excessive CPU consumption in the cleanup(8) service due to
-excessive body_checks.
+excessive body_checks, or (Postfix >= 2.3) high latency milters.
Note, that once the active queue is full, the cleanup service will attempt to
slow down message injection by pausing $in_flow_delay for each message. In this
case "maildrop" queue congestion may be a consequence of congestion downstream,
rather than a problem in its own right.
-Note also, that one should not attempt to deliver large volumes of mail via the
-pickup(8) service. High volume sites must avoid using content filters that
-reinject scanned mail via Postfix sendmail(1) and postdrop(1).
+Note, you should not attempt to deliver large volumes of mail via the pickup(8)
+service. High volume sites should avoid using "simple" content filters that re-
+inject scanned mail via Postfix sendmail(1) and postdrop(1).
A high arrival rate of locally submitted mail may be an indication of an
uncaught forwarding loop, or a run-away notification program. Try to keep the
delivery attempts are made for messages in the "hold" queue. The postsuper(1)
command can be used to manually release messages into the "deferred" queue.
-Messages can potentially stay in the "hold" queue for a time exceeding the
-normal maximal queue lifetime (after which undelivered messages are bounced
-back to the sender). If such "old" messages need to be released from the "hold"
-queue, they should typically be moved into the "maildrop" queue, so that the
-message gets a new timestamp and is given more than one opportunity to be
-delivered. Messages that are "young" can be moved directly into the "deferred"
-queue.
+Messages can potentially stay in the "hold" queue longer than
+$maximal_queue_lifetime. If such "old" messages need to be released from the
+"hold" queue, they should typically be moved into the "maildrop" queue using
+"postsuper -r", so that the message gets a new timestamp and is given more than
+one opportunity to be delivered. Messages that are "young" can be moved
+directly into the "deferred" queue using "postsuper -H".
The "hold" queue plays little role in Postfix performance, and monitoring of
the "hold" queue is typically more closely motivated by tracking spam and
The incoming queue grows when the message input rate spikes above the rate at
which the queue manager can import messages into the active queue. The main
-factor slowing down the queue manager is transport queries to the trivial-
-rewrite service. If the queue manager is routinely not keeping up, consider not
-using "slow" lookup services (MySQL, LDAP, ...) for transport lookups or
-speeding up the hosts that provide the lookup service.
+factors slowing down the queue manager are disk I/O and lookup queries to the
+trivial-rewrite service. If the queue manager is routinely not keeping up,
+consider not using "slow" lookup services (MySQL, LDAP, ...) for transport
+lookups or speeding up the hosts that provide the lookup service. If the
+problem is I/O starvation, consider striping the queue over more disks, faster
+controllers with a battery write cache, or other hardware improvements. At the
+very least, make sure that the queue directory is mounted with the "noatime"
+option if applicable to the underlying filesystem.
The in_flow_delay parameter is used to clamp the input rate when the queue
manager starts to fall behind. The cleanup(8) service will pause for
is capped by the transport's recipient concurrency limit.
Multiple recipient groups (from one or more messages) are queued for delivery
-via the common transport/nexthop combination. The destination concurrency limit
-for the transports caps the number of simultaneous delivery attempts for each
-nexthop. Transports with a recipient concurrency limit of 1 are special: these
-are grouped by the actual recipient address rather than the nexthop, thereby
-enabling per-recipient concurrency limits rather than per-domain concurrency
-limits. Per-recipient limits are appropriate when performing final delivery to
+grouped by transport/nexthop combination. The d\bde\bes\bst\bti\bin\bna\bat\bti\bio\bon\bn concurrency limit for
+the transports caps the number of simultaneous delivery attempts for each
+nexthop. Transports with a r\bre\bec\bci\bip\bpi\bie\ben\bnt\bt concurrency limit of 1 are special: these
+are grouped by the actual recipient address rather than the nexthop, yielding
+per-recipient concurrency limits rather than per-domain concurrency limits.
+Per-recipient limits are appropriate when performing final delivery to
mailboxes rather than when relaying to a remote server.
Congestion occurs in the active queue when one or more destinations drain
-slower than the corresponding message input rate. If a destination is down for
-some time, the queue manager will mark it dead, and immediately defer all mail
-for the destination without trying to assign it to a delivery agent. In this
-case the messages will quickly leave the active queue and end up in the
-deferred queue. If the destination is instead simply slow, or there is a
-problem causing an excessive arrival rate the active queue will grow and will
-become dominated by mail to the congested destination.
+slower than the corresponding message input rate.
+
+Input into the active queue comes both from new mail in the "incoming" queue,
+and retries of mail in the "deferred" queue. Should the "deferred" queue get
+really large, retries of old mail can dominate the arrival rate of new mail.
+Systems with more CPU, faster disks and more network bandwidth can deal with
+larger deferred queues, but as a rule of thumb the deferred queue scales to
+somewhere between 100,000 and 1,000,000 messages with good performance unlikely
+above that "limit". Systems with queues this large should typically stop
+accepting new mail, or put the backlog "on hold" until the underlying issue is
+fixed (provided that there is enough capacity to handle just the new mail).
+
+When a destination is down for some time, the queue manager will mark it dead,
+and immediately defer all mail for the destination without trying to assign it
+to a delivery agent. In this case the messages will quickly leave the active
+queue and end up in the deferred queue (with Postfix < 2.4, this is done
+directly by the queue manager, with Postfix >= 2.4 this is done via the "retry"
+delivery agent).
+
+When the destination is instead simply slow, or there is a problem causing an
+excessive arrival rate the active queue will grow and will become dominated by
+mail to the congested destination.
The only way to reduce congestion is to either reduce the input rate or
increase the throughput. Increasing the throughput requires either increasing
the system and network are not loaded, raise the "smtp" and/or "relay" process
limits!
-Especially for the "relay" transport, consider lower SMTP connection timeouts
-(1-5 seconds) and higher than default destination concurrency limits. Compute
-the expected latency when 1 out of N of the MX hosts for a high volume site is
-down and not responding, and make sure that the configured concurrency divided
-by this latency exceeds the required steady-state message rate. If the
-destination is managed by you, consider load balancers in front of groups of MX
-hosts. Load balancers have higher uptime and will be able to hide individual MX
-host failures.
-
-If necessary, dedicate and tune custom transports for high volume destinations.
+When a high volume destination is served by multiple MX hosts with typically
+low delivery latency, performance can suffer dramatically when one of the MX
+hosts is unresponsive and SMTP connections to that host timeout. For example,
+if there are 2 equal weight MX hosts, the SMTP connection timeout is 30 seconds
+and one of the MX hosts is down, the average SMTP connection will take
+approximately 15 seconds to complete. With a default per-destination
+concurrency limit of 20 connections, throughput falls to just over 1 message
+per second.
+
+The best way to avoid bottlenecks when one or more MX hosts is non-responsive
+is to use connection caching. Connection caching was introduced with Postfix
+2.2 and is by default enabled on demand for destinations with a backlog of mail
+in the active queue. When connection caching is in effect for a particular
+destination, established connections are re-used to send additional messages,
+this reduces the number of connections made per message delivery and maintains
+good throughput even in the face of partial unavailability of the destination's
+MX hosts.
+
+If connection caching is not available (Postfix < 2.2) or does not provide a
+sufficient latency reduction, especially for the "relay" transport used to
+forward mail to "your own" domains, consider setting lower than default SMTP
+connection timeouts (1-5 seconds) and higher than default destination
+concurrency limits. This will further reduce latency and provide more
+concurrency to maintain throughput should latency rise.
+
+Setting high concurrency limits to domains that are not your own may be viewed
+as hostile by the receiving system, and steps may be taken to prevent you from
+monopolizing the destination system's resources. The defensive measures may
+substantially reduce your throughput or block access entirely. Do not set
+aggressive concurrency limits to remote domains without coordinating with the
+administrators of the target domain.
+
+If necessary, dedicate and tune custom transports for selected high volume
+destinations. The "relay" transport is provided for forwarding mail to domains
+for which your server is a primary or backup MX host. These can make up a
+substantial fraction of your email traffic. Use the "relay" and not the "smtp"
+transport to send email to these domains. Using the "relay" transport allocates
+a separate delivery agent pool to these destinations and allows separate tuning
+of timeouts and concurrency limits.
Another common cause of congestion is unwarranted flushing of the entire
deferred queue. The deferred queue holds messages that are likely to fail to be
-delivered and are also likely to be slow to fail delivery (timeouts). This
-means that the most common reaction to a large deferred queue (flush it!) is
-more than likely counter- productive, and is likely to make the problem worse.
-Do not flush the deferred queue unless you expect that most of its content has
+delivered and are also likely to be slow to fail delivery (time out). As a
+result the most common reaction to a large deferred queue (flush it!) is more
+than likely counter-productive, and typically makes the congestion worse. Do
+not flush the deferred queue unless you expect that most of its content has
recently become deliverable (e.g. relayhost back up after an outage)!
Note that whenever the queue manager is restarted, there may already be
normal incoming queue scan to refill the active queue. The process of moving
all the messages back and forth, redoing transport table (trivial-rewrite(8)
resolve service) lookups, and re-importing the messages back into memory is
-expensive. At all costs, avoid frequent restarts of the queue manager.
+expensive. At all costs, avoid frequent restarts of the queue manager (e.g. via
+frequent execution of "postfix reload").
T\bTh\bhe\be "\b"d\bde\bef\bfe\ber\brr\bre\bed\bd"\b" q\bqu\bue\beu\bue\be
controlled by the queue_run_delay parameter. While a deferred queue scan is in
progress, if an incoming queue scan is also in progress (ideally these are
brief since the incoming queue should be short), the queue manager alternates
-between bringing a new "incoming" message and a new "deferred" message into the
+between looking for messages in the "incoming" queue and in the "deferred"
queue. This "round-robin" strategy prevents starvation of either the incoming
or the deferred queues.
Each deferred queue scan only brings a fraction of the deferred queue back into
the active queue for a retry. This is because each message in the deferred
queue is assigned a "cool-off" time when it is deferred. This is done by time-
-warping the modification times of the queue file into the future. The queue
-file is not eligible for a retry if its modification time is not yet reached.
+warping the modification time of the queue file into the future. The queue file
+is not eligible for a retry if its modification time is not yet reached.
The "cool-off" time is at least $minimal_backoff_time and at most
$maximal_backoff_time. The next retry time is set by doubling the message's age
If a high volume site routinely has large deferred queues, it may be useful to
adjust the queue_run_delay, minimal_backoff_time and maximal_backoff_time to
-provide short enough delays on first failure, with perhaps longer delays after
-multiple failures, to reduce the retransmission rate of old messages and
-thereby reduce the quantity of previously deferred mail in the active queue.
+provide short enough delays on first failure (Postfix >= 2.4 has a sensibly low
+minimal backoff time by default), with perhaps longer delays after multiple
+failures, to reduce the retransmission rate of old messages and thereby reduce
+the quantity of previously deferred mail in the active queue. If you want a
+really low minimal_backoff_time, you may also want to lower queue_run_delay,
+but understand that more frequent scans will increase the demand for disk I/O.
One common cause of large deferred queues is failure to validate recipients at
the SMTP input stage. Since spammers routinely launch dictionary attacks from
unrepliable sender addresses, the bounces for invalid recipient addresses clog
the deferred queue (and at high volumes proportionally clog the active queue).
Recipient validation is strongly recommended through use of the
-local_recipient_maps and relay_recipient_maps parameters.
+local_recipient_maps and relay_recipient_maps parameters. Even when bounces
+drain quickly they inundate innocent victims of forgery with unwanted email. To
+avoid this, do not accept mail for invalid recipients.
When a host with lots of deferred mail is down for some time, it is possible
for the entire deferred queue to reach its retry time simultaneously. This can
lead to a very full active queue once the host comes back up. The phenomenon
can repeat approximately every maximal_backoff_time seconds if the messages are
-again deferred after a brief burst of congestion. Ideally, in the future
-Postfix will add a random offset to the retry time (or use a combination of
-strategies) to reduce the chances of repeated complete deferred queue flushes.
+again deferred after a brief burst of congestion. Perhaps, a future Postfix
+release will add a random offset to the retry time (or use a combination of
+strategies) to reduce the odds of repeated complete deferred queue flushes.
C\bCr\bre\bed\bdi\bit\bts\bs
- Replace SPF policy server script by link to SPF website.
- Remove MacOS X examples. They have not been updated.
+
+- Is "postmap -qf" still needed with regexp/pcre maps?
# \fBqshape\fR [\fB-s\fR] [\fB-p\fR] [\fB-m \fImin_subdomains\fR]
# [\fB-b \fIbucket_count\fR] [\fB-t \fIbucket_time\fR]
# [\fB-l\fR] [\fB-w \fIterminal_width\fR]
+# [\fB-N \fIbatch_msg_count\fR] [\fB-n \fIbatch_top_domains\fR]
# [\fB-c \fIconfig_directory\fR] [\fIqueue_name\fR ...]
# DESCRIPTION
# The \fBqshape\fR program helps the administrator understand the
# parent domain rows are shown as '.+' followed by the last 16 bytes
# of the domain name. If this is still too narrow to show the domain
# name and all the counters, the terminal_width limit is violated.
+# .IP "\fB-N \fIbatch_msg_count\fR"
+# When the output device is a terminal, intermediate results are
+# shown each "batch_msg_count" messages. This produces usable results
+# in a reasonable time even when the deferred queue is large. The
+# default is to show intermediate results every 1000 messages.
+# .IP "\fB-n \fIbatch_top_domains\fR"
+# When reporting intermediate or final results to a termainal, report
+# only the top "batch_top_domains" domains. The default limit is 20
+# domains.
# .IP "\fB-c \fIconfig_directory\fR"
# The \fBmain.cf\fR configuration file is in the named directory
# instead of the default configuration directory.
use File::Find;
use Getopt::Std;
+my $cls; # Clear screen escape sequence
+my $batch_msg_count; # Interim result frequency
+my $batch_top_domains; # Interim result count
my %opts; # Command line switches
my %q; # domain counts for queues and buckets
my %sub; # subdomain counts for parent domains
warn "$0: $_[0]" unless exists($opts{"h"});
die "Usage: $0 [ -s ] [ -p ] [ -m <min_subdomains> ] [ -l ]\n".
"\t[ -b <bucket_count> ] [ -t <bucket_time> ] [ -w <terminal_width> ]\n".
+ "\t[ -N <batch_msg_count> ] [ -n <batch_top_domains> ]\n".
"\t[ -c <config_directory> ] [ <queue_name> ... ]\n".
"The 's' option shows sender domain counts.\n".
"The 'p' option shows address counts by for parent domains.\n".
"not supported. If necessary, use explicit absolute paths for all queues.\n";
};
- getopts("lhc:psw:b:t:m:", \%opts);
+ getopts("lhc:psw:b:t:m:n:N:", \%opts);
warn "Help message" if (exists $opts{"h"});
@qlist = @ARGV if (@ARGV > 0);
$tick = $opts{"t"} if (exists $opts{"t"} && $opts{"t"} > 0);
$minsub = $opts{"m"} if (exists $opts{"m"} && $opts{"m"} > 0);
+if ( -t STDOUT ) {
+ $batch_msg_count = 1000 unless defined($batch_msg_count = $opts{"N"});
+ $batch_top_domains = 20 unless defined ($batch_top_domains = $opts{"n"});
+ $cls = `clear`;
+} else {
+ $batch_msg_count = 0;
+ $batch_top_domains = 0;
+ $cls = "";
+}
+
sub rec_get {
my ($h) = @_;
my $r = getc($h) || return;
# Collate by age of message in the selected queues.
#
+my $msgs;
sub wanted {
if (my ($t, $s, @r) = qenv($_)) {
my $b = bucket($t, $now);
$new = ! $old;
} while ($opts{"p"} && $a =~ s/^(?:\.)?[^.]+\.(.*\.)/.$1/);
}
+ if ($batch_msg_count > 0 && ++$msgs % $batch_msg_count == 0) {
+ results();
+ }
}
}
-find(\&wanted, @qlist);
my @heads;
-my $fmt = "";
-my $dw = $width;
-
-for (my $i = 0, my $t = 0; $i <= $bnum; ) {
- $q{"TOTAL"}->[$i] ||= 0;
- my $l = length($q{"TOTAL"}->[$i]);
- my $h = ($i == 0) ? "T" : $t;
- $l = length($h) if (length($h) >= $l);
- $l = ($l > 2) ? $l + 1 : 3;
- push(@heads, $h);
- $fmt .= sprintf "%%%ds", $l;
- $dw -= $l;
- if (++$i < $bnum) { $t += ($t && !$opts{"l"}) ? $t : $tick; } else { $t = "$t+"; }
-}
-$dw = $dwidth if ($dw < $dwidth);
+my $fmt;
+my $dw;
sub pdomain {
my ($d, @count) = @_;
printf "$fmt\n", @count;
}
-# Print headings
-#
-pdomain("", @heads);
+sub results {
+ @heads = ();
+ $dw = $width;
+ $fmt = "";
+ for (my $i = 0, my $t = 0; $i <= $bnum; ) {
+ $q{"TOTAL"}->[$i] ||= 0;
+ my $l = length($q{"TOTAL"}->[$i]);
+ my $h = ($i == 0) ? "T" : $t;
+ $l = length($h) if (length($h) >= $l);
+ $l = ($l > 2) ? $l + 1 : 3;
+ push(@heads, $h);
+ $fmt .= sprintf "%%%ds", $l;
+ $dw -= $l;
+ if (++$i < $bnum) { $t += ($t && !$opts{"l"}) ? $t : $tick; } else { $t = "$t+"; }
+ }
+ $dw = $dwidth if ($dw < $dwidth);
-# Show per-domain totals
-#
-foreach my $d (sort { $q{$b}->[0] <=> $q{$a}->[0] ||
- length($a) <=> length($b) } keys %q) {
+ print $cls if ($batch_msg_count > 0);
- # Skip parent domains with < $minsub subdomains.
+ # Print headings
#
- next if ($d =~ /^\./ && $sub{$d} < $minsub);
+ pdomain("", @heads);
- pdomain($d, @{$q{$d}});
+ my $n = 0;
+
+ # Show per-domain totals
+ #
+ foreach my $d (sort { $q{$b}->[0] <=> $q{$a}->[0] ||
+ length($a) <=> length($b) } keys %q) {
+
+ # Skip parent domains with < $minsub subdomains.
+ #
+ next if ($d =~ /^\./ && $sub{$d} < $minsub);
+
+ last if ($batch_top_domains > 0 && ++$n > $batch_top_domains);
+
+ pdomain($d, @{$q{$d}});
+ }
}
+
+find(\&wanted, @qlist);
+results();
# ACCESS(5) ACCESS(5)
#
# NAME
-# access - Postfix access table format
+# access - Postfix SMTP server access table
#
# SYNOPSIS
# postmap /etc/postfix/access
# postmap -q - /etc/postfix/access <inputfile
#
# DESCRIPTION
-# The optional access(5) table directs the Postfix SMTP
-# server to selectively reject or accept mail. Access can be
-# allowed or denied for specific host names, domain names,
-# networks, host addresses or mail addresses.
-#
-# For an example, see the EXAMPLE section at the end of this
-# manual page.
-#
-# Normally, the access(5) table is specified as a text file
-# that serves as input to the postmap(1) command. The
-# result, an indexed file in dbm or db format, is used for
-# fast searching by the mail system. Execute the command
-# "postmap /etc/postfix/access" in order to rebuild the
-# indexed file after changing the access table.
-#
-# When the table is provided via other means such as NIS,
-# LDAP or SQL, the same lookups are done as for ordinary
+# The Postfix SMTP server access(5) table specifies actions
+# that are triggered by information from or about remote
+# SMTP clients: host names, network addresses, or email
+# addresses. An action may grant or deny access, or it may
+# change the way that an email transaction will be handled.
+#
+# Normally, the access(5) table is specified as a text file
+# that serves as input to the postmap(1) command. The
+# result, an indexed file in dbm or db format, is used for
+# fast searching by the mail system. Execute the command
+# "postmap /etc/postfix/access" to rebuild an indexed file
+# after changing the corresponding text file.
+#
+# When the table is provided via other means such as NIS,
+# LDAP or SQL, the same lookups are done as for ordinary
# indexed files.
#
-# Alternatively, the table can be provided as a regular-
+# Alternatively, the table can be provided as a regular-
# expression map where patterns are given as regular expres-
-# sions, or lookups can be directed to TCP-based server. In
-# that case, the lookups are done in a slightly different
-# way as described below under "REGULAR EXPRESSION TABLES"
-# and "TCP-BASED TABLES".
+# sions, or lookups can be directed to TCP-based server. In
+# those cases, the lookups are done in a slightly different
+# way as described below under "REGULAR EXPRESSION TABLES"
+# or "TCP-BASED TABLES".
#
# CASE FOLDING
-# The search string is folded to lowercase before database
-# lookup. As of Postfix 2.3, the search string is not case
-# folded with database types such as regexp: or pcre: whose
+# The search string is folded to lowercase before database
+# lookup. As of Postfix 2.3, the search string is not case
+# folded with database types such as regexp: or pcre: whose
# lookup fields can match both upper and lower case.
#
# TABLE FORMAT
# address, perform the corresponding action.
#
# blank lines and comments
-# Empty lines and whitespace-only lines are ignored,
-# as are lines whose first non-whitespace character
+# Empty lines and whitespace-only lines are ignored,
+# as are lines whose first non-whitespace character
# is a `#'.
#
# multi-line text
-# A logical line starts with non-whitespace text. A
-# line that starts with whitespace continues a logi-
+# A logical line starts with non-whitespace text. A
+# line that starts with whitespace continues a logi-
# cal line.
#
# EMAIL ADDRESS PATTERNS
# With lookups from indexed files such as DB or DBM, or from
-# networked tables such as NIS, LDAP or SQL, patterns are
+# networked tables such as NIS, LDAP or SQL, patterns are
# tried in the order as listed below:
#
# user@domain
# Matches the specified mail address.
#
# domain.tld
-# Matches domain.tld as the domain part of an email
+# Matches domain.tld as the domain part of an email
# address.
#
# The pattern domain.tld also matches subdomains, but
# only when the string smtpd_access_maps is listed in
-# the Postfix parent_domain_matches_subdomains con-
-# figuration setting (note that this is the default
-# for some versions of Postfix). Otherwise, specify
-# .domain.tld (note the initial dot) in order to
+# the Postfix parent_domain_matches_subdomains con-
+# figuration setting (note that this is the default
+# for some versions of Postfix). Otherwise, specify
+# .domain.tld (note the initial dot) in order to
# match subdomains.
#
-# user@ Matches all mail addresses with the specified user
+# user@ Matches all mail addresses with the specified user
# part.
#
-# Note: lookup of the null sender address is not possible
-# with some types of lookup table. By default, Postfix uses
-# <> as the lookup key for such addresses. The value is
-# specified with the smtpd_null_access_lookup_key parameter
+# Note: lookup of the null sender address is not possible
+# with some types of lookup table. By default, Postfix uses
+# <> as the lookup key for such addresses. The value is
+# specified with the smtpd_null_access_lookup_key parameter
# in the Postfix main.cf file.
#
# EMAIL ADDRESS EXTENSION
# When a mail address localpart contains the optional recip-
-# ient delimiter (e.g., user+foo@domain), the lookup order
-# becomes: user+foo@domain, user@domain, domain, user+foo@,
+# ient delimiter (e.g., user+foo@domain), the lookup order
+# becomes: user+foo@domain, user@domain, domain, user+foo@,
# and user@.
#
# HOST NAME/ADDRESS PATTERNS
# With lookups from indexed files such as DB or DBM, or from
-# networked tables such as NIS, LDAP or SQL, the following
+# networked tables such as NIS, LDAP or SQL, the following
# lookup patterns are examined in the order as listed:
#
# domain.tld
#
# The pattern domain.tld also matches subdomains, but
# only when the string smtpd_access_maps is listed in
-# the Postfix parent_domain_matches_subdomains con-
+# the Postfix parent_domain_matches_subdomains con-
# figuration setting. Otherwise, specify .domain.tld
-# (note the initial dot) in order to match subdo-
+# (note the initial dot) in order to match subdo-
# mains.
#
# net.work.addr.ess
#
# net.work
#
-# net Matches the specified IPv4 host address or subnet-
-# work. An IPv4 host address is a sequence of four
+# net Matches the specified IPv4 host address or subnet-
+# work. An IPv4 host address is a sequence of four
# decimal octets separated by ".".
#
-# Subnetworks are matched by repeatedly truncating
+# Subnetworks are matched by repeatedly truncating
# the last ".octet" from the remote IPv4 host address
-# string until a match is found in the access table,
+# string until a match is found in the access table,
# or until further truncation is not possible.
#
# NOTE 1: The information in the access map should be
# in canonical form, with unnecessary null characters
-# eliminated. Address information must not be
+# eliminated. Address information must not be
# enclosed with "[]" characters.
#
-# NOTE 2: use the cidr lookup table type to specify
+# NOTE 2: use the cidr lookup table type to specify
# network/netmask patterns. See cidr_table(5) for
# details.
#
#
# net:work
#
-# net Matches the specified IPv6 host address or subnet-
-# work. An IPv6 host address is a sequence of three
-# to eight hexadecimal octet pairs separated by ":".
+# net Matches the specified IPv6 host address or subnet-
+# work. An IPv6 host address is a sequence of three
+# to eight hexadecimal octet pairs separated by ":".
#
-# Subnetworks are matched by repeatedly truncating
-# the last ":octetpair" from the remote IPv6 host
+# Subnetworks are matched by repeatedly truncating
+# the last ":octetpair" from the remote IPv6 host
# address string until a match is found in the access
# table, or until further truncation is not possible.
#
#
# NOTE 2: The information in the access map should be
# in canonical form, with unnecessary null characters
-# eliminated. Address information must not be
+# eliminated. Address information must not be
# enclosed with "[]" characters.
#
-# NOTE 3: use the cidr lookup table type to specify
+# NOTE 3: use the cidr lookup table type to specify
# network/netmask patterns. See cidr_table(5) for
# details.
#
#
# all-numerical
# An all-numerical result is treated as OK. This for-
-# mat is generated by address-based relay authoriza-
+# mat is generated by address-based relay authoriza-
# tion schemes such as pop-before-smtp.
#
# REJECT ACTIONS
-# Postfix version 2.3 and later support enhanced status
-# codes as defined in RFC 3463. When no code is specified
-# at the beginning of the text below, Postfix inserts a
-# default enhanced status code of "5.7.1" in the case of
-# reject actions, and "4.7.1" in the case of defer actions.
+# Postfix version 2.3 and later support enhanced status
+# codes as defined in RFC 3463. When no code is specified
+# at the beginning of the text below, Postfix inserts a
+# default enhanced status code of "5.7.1" in the case of
+# reject actions, and "4.7.1" in the case of defer actions.
# See "ENHANCED STATUS CODES" below.
#
# 4NN text
#
# 5NN text
-# Reject the address etc. that matches the pattern,
+# Reject the address etc. that matches the pattern,
# and respond with the numerical three-digit code and
-# text. 4NN means "try again later", while 5NN means
+# text. 4NN means "try again later", while 5NN means
# "do not try again".
#
-# The reply code "421" causes Postfix to disconnect
+# The reply code "421" causes Postfix to disconnect
# immediately (Postfix version 2.3 and later).
#
# REJECT optional text...
-# Reject the address etc. that matches the pattern.
-# Reply with $reject_code optional text... when the
-# optional text is specified, otherwise reply with a
+# Reject the address etc. that matches the pattern.
+# Reply with $reject_code optional text... when the
+# optional text is specified, otherwise reply with a
# generic error response message.
#
# DEFER_IF_REJECT optional text...
-# Defer the request if some later restriction would
+# Defer the request if some later restriction would
# result in a REJECT action. Reply with "450 optional
# text... when the optional text is specified, other-
# wise reply with a generic error response message.
# This feature is available in Postfix 2.1 and later.
#
# DEFER_IF_PERMIT optional text...
-# Defer the request if some later restriction would
-# result in a an explicit or implicit PERMIT action.
-# Reply with "450 optional text... when the optional
-# text is specified, otherwise reply with a generic
+# Defer the request if some later restriction would
+# result in a an explicit or implicit PERMIT action.
+# Reply with "450 optional text... when the optional
+# text is specified, otherwise reply with a generic
# error response message.
#
# This feature is available in Postfix 2.1 and later.
# reject_unauth_destination, and so on).
#
# DISCARD optional text...
-# Claim successful delivery and silently discard the
-# message. Log the optional text if specified, oth-
+# Claim successful delivery and silently discard the
+# message. Log the optional text if specified, oth-
# erwise log a generic message.
#
-# Note: this action currently affects all recipients
-# of the message. To discard only one recipient
-# without discarding the entire message, use the
+# Note: this action currently affects all recipients
+# of the message. To discard only one recipient
+# without discarding the entire message, use the
# transport(5) table to direct mail to the discard(8)
# service.
#
# This feature is available in Postfix 2.0 and later.
#
-# DUNNO Pretend that the lookup key was not found. This
-# prevents Postfix from trying substrings of the
-# lookup key (such as a subdomain name, or a network
+# DUNNO Pretend that the lookup key was not found. This
+# prevents Postfix from trying substrings of the
+# lookup key (such as a subdomain name, or a network
# address subnetwork).
#
# This feature is available in Postfix 2.0 and later.
#
# FILTER transport:destination
-# After the message is queued, send the entire mes-
+# After the message is queued, send the entire mes-
# sage through the specified external content filter.
-# The transport:destination syntax is described in
-# the transport(5) manual page. More information
-# about external content filters is in the Postfix
+# The transport:destination syntax is described in
+# the transport(5) manual page. More information
+# about external content filters is in the Postfix
# FILTER_README file.
#
-# Note: this action overrides the main.cf con-
+# Note: this action overrides the main.cf con-
# tent_filter setting, and currently affects all
# recipients of the message.
#
# This feature is available in Postfix 2.0 and later.
#
# HOLD optional text...
-# Place the message on the hold queue, where it will
-# sit until someone either deletes it or releases it
-# for delivery. Log the optional text if specified,
+# Place the message on the hold queue, where it will
+# sit until someone either deletes it or releases it
+# for delivery. Log the optional text if specified,
# otherwise log a generic message.
#
-# Mail that is placed on hold can be examined with
-# the postcat(1) command, and can be destroyed or
+# Mail that is placed on hold can be examined with
+# the postcat(1) command, and can be destroyed or
# released with the postsuper(1) command.
#
-# Note: use "postsuper -r" to release mail that was
-# kept on hold for a significant fraction of $maxi-
+# Note: use "postsuper -r" to release mail that was
+# kept on hold for a significant fraction of $maxi-
# mal_queue_lifetime or $bounce_queue_lifetime, or
# longer.
#
-# Note: this action currently affects all recipients
+# Note: this action currently affects all recipients
# of the message.
#
# This feature is available in Postfix 2.0 and later.
#
# PREPEND headername: headervalue
-# Prepend the specified message header to the mes-
-# sage. When this action is used multiple times, the
-# first prepended header appears before the second
-# etc. prepended header.
+# Prepend the specified message header to the mes-
+# sage. When this action executes multiple times,
+# the first prepended header appears before the sec-
+# ond etc. prepended header.
#
-# Note: this action does not support multi-line mes-
+# Note: this action does not support multi-line mes-
# sage headers.
#
-# Note: this action must be used before the message
-# content is received; it cannot be used in
-# smtpd_end_of_data_restrictions.
+# Note: this action must execute before the message
+# content is received; it cannot execute in the con-
+# text of smtpd_end_of_data_restrictions.
#
# This feature is available in Postfix 2.1 and later.
#
# REDIRECT user@domain
-# After the message is queued, send the message to
+# After the message is queued, send the message to
# the specified address instead of the intended
# recipient(s).
#
-# Note: this action overrides the FILTER action, and
+# Note: this action overrides the FILTER action, and
# currently affects all recipients of the message.
#
# This feature is available in Postfix 2.1 and later.
#
# WARN optional text...
# Log a warning with the optional text, together with
-# client information and if available, with helo,
+# client information and if available, with helo,
# sender, recipient and protocol information.
#
# This feature is available in Postfix 2.1 and later.
#
# ENHANCED STATUS CODES
-# Postfix version 2.3 and later support enhanced status
-# codes as defined in RFC 3463. When an enhanced status
-# code is specified in an access table, it is subject to
-# modification. The following transformations are needed
-# when the same access table is used for client, helo,
-# sender, or recipient access restrictions; they happen
+# Postfix version 2.3 and later support enhanced status
+# codes as defined in RFC 3463. When an enhanced status
+# code is specified in an access table, it is subject to
+# modification. The following transformations are needed
+# when the same access table is used for client, helo,
+# sender, or recipient access restrictions; they happen
# regardless of whether Postfix replies to a MAIL FROM, RCPT
# TO or other SMTP command.
#
-# o When a sender address matches a REJECT action, the
-# Postfix SMTP server will transform a recipient DSN
-# status (e.g., 4.1.1-4.1.6) into the corresponding
+# o When a sender address matches a REJECT action, the
+# Postfix SMTP server will transform a recipient DSN
+# status (e.g., 4.1.1-4.1.6) into the corresponding
# sender DSN status, and vice versa.
#
-# o When non-address information matches a REJECT
-# action (such as the HELO command argument or the
-# client hostname/address), the Postfix SMTP server
-# will transform a sender or recipient DSN status
-# into a generic non-address DSN status (e.g.,
+# o When non-address information matches a REJECT
+# action (such as the HELO command argument or the
+# client hostname/address), the Postfix SMTP server
+# will transform a sender or recipient DSN status
+# into a generic non-address DSN status (e.g.,
# 4.0.0).
#
# REGULAR EXPRESSION TABLES
-# This section describes how the table lookups change when
+# This section describes how the table lookups change when
# the table is given in the form of regular expressions. For
-# a description of regular expression lookup table syntax,
+# a description of regular expression lookup table syntax,
# see regexp_table(5) or pcre_table(5).
#
-# Each pattern is a regular expression that is applied to
+# Each pattern is a regular expression that is applied to
# the entire string being looked up. Depending on the appli-
-# cation, that string is an entire client hostname, an
+# cation, that string is an entire client hostname, an
# entire client IP address, or an entire mail address. Thus,
# no parent domain or parent network search is done,
-# user@domain mail addresses are not broken up into their
+# user@domain mail addresses are not broken up into their
# user@ and domain constituent parts, nor is user+foo broken
# up into user and foo.
#
-# Patterns are applied in the order as specified in the ta-
-# ble, until a pattern is found that matches the search
+# Patterns are applied in the order as specified in the ta-
+# ble, until a pattern is found that matches the search
# string.
#
-# Actions are the same as with indexed file lookups, with
-# the additional feature that parenthesized substrings from
+# Actions are the same as with indexed file lookups, with
+# the additional feature that parenthesized substrings from
# the pattern can be interpolated as $1, $2 and so on.
#
# TCP-BASED TABLES
-# This section describes how the table lookups change when
+# This section describes how the table lookups change when
# lookups are directed to a TCP-based server. For a descrip-
# tion of the TCP client/server lookup protocol, see tcp_ta-
# ble(5). This feature is not available up to and including
# Postfix version 2.4.
#
-# Each lookup operation uses the entire query string once.
-# Depending on the application, that string is an entire
+# Each lookup operation uses the entire query string once.
+# Depending on the application, that string is an entire
# client hostname, an entire client IP address, or an entire
-# mail address. Thus, no parent domain or parent network
-# search is done, user@domain mail addresses are not broken
-# up into their user@ and domain constituent parts, nor is
+# mail address. Thus, no parent domain or parent network
+# search is done, user@domain mail addresses are not broken
+# up into their user@ and domain constituent parts, nor is
# user+foo broken up into user and foo.
#
# Actions are the same as with indexed file lookups.
#
# EXAMPLE
-# The following example uses an indexed file, so that the
-# order of table entries does not matter. The example per-
-# mits access by the client at address 1.2.3.4 but rejects
-# all other clients in 1.2.3.0/24. Instead of hash lookup
-# tables, some systems use dbm. Use the command "postconf
-# -m" to find out what lookup tables Postfix supports on
+# The following example uses an indexed file, so that the
+# order of table entries does not matter. The example per-
+# mits access by the client at address 1.2.3.4 but rejects
+# all other clients in 1.2.3.0/24. Instead of hash lookup
+# tables, some systems use dbm. Use the command "postconf
+# -m" to find out what lookup tables Postfix supports on
# your system.
#
# /etc/postfix/main.cf:
# editing the file.
#
# BUGS
-# The table format does not understand quoting conventions.
+# The table format does not understand quoting conventions.
#
# SEE ALSO
# postmap(1), Postfix lookup table manager
# transport(5), transport:nexthop syntax
#
# README FILES
-# Use "postconf readme_directory" or "postconf html_direc-
+# Use "postconf readme_directory" or "postconf html_direc-
# tory" to locate this information.
# SMTPD_ACCESS_README, built-in SMTP server access control
# DATABASE_README, Postfix lookup table overview
#
# LICENSE
-# The Secure Mailer license must be distributed with this
+# The Secure Mailer license must be distributed with this
# software.
#
# AUTHOR(S)
# file that serves as input to the postmap(1) command. The
# result, an indexed file in dbm or db format, is used for
# fast searching by the mail system. Execute the command
-# "postmap /etc/postfix/canonical" in order to rebuild the
-# indexed file after changing the text file.
+# "postmap /etc/postfix/canonical" to rebuild an indexed
+# file after changing the corresponding text file.
#
# When the table is provided via other means such as NIS,
# LDAP or SQL, the same lookups are done as for ordinary
# Alternatively, the table can be provided as a regular-
# expression map where patterns are given as regular expres-
# sions, or lookups can be directed to TCP-based server. In
-# that case, the lookups are done in a slightly different
+# those cases, the lookups are done in a slightly different
# way as described below under "REGULAR EXPRESSION TABLES"
-# and "TCP-BASED TABLES".
+# or "TCP-BASED TABLES".
#
# By default the canonical(5) mapping affects both message
# header addresses (i.e. addresses that appear inside mes-
# that serves as input to the postmap(1) command. The
# result, an indexed file in dbm or db format, is used for
# fast searching by the mail system. Execute the command
-# "postmap /etc/postfix/generic" in order to rebuild the
-# indexed file after changing the text file.
+# "postmap /etc/postfix/generic" to rebuild an indexed file
+# after changing the corresponding text file.
#
# When the table is provided via other means such as NIS,
# LDAP or SQL, the same lookups are done as for ordinary
# Alternatively, the table can be provided as a regular-
# expression map where patterns are given as regular expres-
# sions, or lookups can be directed to TCP-based server. In
-# that case, the lookups are done in a slightly different
+# those case, the lookups are done in a slightly different
# way as described below under "REGULAR EXPRESSION TABLES"
-# and "TCP-BASED TABLES".
+# or "TCP-BASED TABLES".
#
# CASE FOLDING
# The search string is folded to lowercase before database
# file that serves as input to the postmap(1) command. The
# result, an indexed file in dbm or db format, is used for
# fast searching by the mail system. Execute the command
-# "postmap /etc/postfix/relocated" in order to rebuild the
-# indexed file after changing the relocated table.
+# "postmap /etc/postfix/relocated" to rebuild an indexed
+# file after changing the corresponding relocated table.
#
# When the table is provided via other means such as NIS,
# LDAP or SQL, the same lookups are done as for ordinary
# Alternatively, the table can be provided as a regular-
# expression map where patterns are given as regular expres-
# sions, or lookups can be directed to TCP-based server. In
-# that case, the lookups are done in a slightly different
+# those case, the lookups are done in a slightly different
# way as described below under "REGULAR EXPRESSION TABLES"
-# and "TCP-BASED TABLES".
+# or "TCP-BASED TABLES".
#
# Table lookups are case insensitive.
#
# file that serves as input to the postmap(1) command. The
# result, an indexed file in dbm or db format, is used for
# fast searching by the mail system. Execute the command
-# "postmap /etc/postfix/transport" in order to rebuild the
-# indexed file after changing the transport table.
+# "postmap /etc/postfix/transport" to rebuild an indexed
+# file after changing the corresponding transport table.
#
# When the table is provided via other means such as NIS,
# LDAP or SQL, the same lookups are done as for ordinary
# Alternatively, the table can be provided as a regular-
# expression map where patterns are given as regular expres-
# sions, or lookups can be directed to TCP-based server. In
-# that case, the lookups are done in a slightly different
+# those case, the lookups are done in a slightly different
# way as described below under "REGULAR EXPRESSION TABLES"
-# and "TCP-BASED TABLES".
+# or "TCP-BASED TABLES".
#
# CASE FOLDING
# The search string is folded to lowercase before database
# text file that serves as input to the postmap(1) command.
# The result, an indexed file in dbm or db format, is used
# for fast searching by the mail system. Execute the command
-# "postmap /etc/postfix/virtual" in order to rebuild the
-# indexed file after changing the text file.
+# "postmap /etc/postfix/virtual" to rebuild an indexed file
+# after changing the corresponding text file.
#
# When the table is provided via other means such as NIS,
# LDAP or SQL, the same lookups are done as for ordinary
# Alternatively, the table can be provided as a regular-
# expression map where patterns are given as regular expres-
# sions, or lookups can be directed to TCP-based server. In
-# that case, the lookups are done in a slightly different
+# those case, the lookups are done in a slightly different
# way as described below under "REGULAR EXPRESSION TABLES"
-# and "TCP-BASED TABLES".
+# or "TCP-BASED TABLES".
#
# CASE FOLDING
# The search string is folded to lowercase before database
<h2>Purpose of this document </h2>
-<p> This document describes the <a href="qshape.1.html">qshape(1)</a> program which helps the
-administrator understand the Postfix queue message distribution
-sorted by time and by sender or recipient domain. <a href="qshape.1.html">qshape(1)</a> is
-bundled with the Postfix 2.1 source under the "auxiliary" directory.
-</p>
-
-<p> In order to understand the output of <a href="qshape.1.html">qshape(1)</a>, it useful to
-understand the various Postfix queues. To this end the role of each
-Postfix queue directory is described briefly in the "Background
-info: Postfix queue directories" section near the end of this
-document. </p>
+<p> This document is an introduction to Postfix queue congestion analysis.
+It explains how the <a href="qshape.1.html">qshape(1)</a> program can help to track down the
+reason for queue congestion. <a href="qshape.1.html">qshape(1)</a> is bundled with Postfix
+2.1 and later source code, under the "auxiliary" directory. This
+document describes <a href="qshape.1.html">qshape(1)</a> as bundled with Postfix 2.4. </p>
<p> This document covers the following topics: </p>
<li><a href="#backlog">Example 4: High volume destination backlog</a>
-<li><a href="#queues">Background info: Postfix queue directories</a>
+<li><a href="#queues">Postfix queue directories</a>
<ul>
<h2><a name="qshape">Introducing the qshape tool</a></h2>
-
<p> When mail is draining slowly or the queue is unexpectedly large,
run <a href="qshape.1.html">qshape(1)</a> as the super-user (root) to help zero in on the problem.
The <a href="qshape.1.html">qshape(1)</a> program displays a tabular view of the Postfix queue
</ul>
+<p> When the output is a terminal intermediate results showing the top 20
+domains (-n option) are displayed after every 1000 messages (-N option)
+and the final output also shows only the top 20 domains. This makes
+qshape useful even when the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> is very large and it may
+otherwise take prohibitively long to read the entire <a href="QSHAPE_README.html#deferred_queue">deferred queue</a>. </p>
+
<p> By default, qshape shows statistics for the union of both the
<a href="QSHAPE_README.html#incoming_queue">incoming</a> and <a href="QSHAPE_README.html#active_queue">active queues</a> which are the most relevant queues to
look at when analyzing performance. </p>
<blockquote>
<pre>
-$ qshape deferred | less
-$ qshape incoming active deferred | less
+$ qshape deferred
+$ qshape incoming active deferred
</pre>
</blockquote>
<p> The problem destinations or sender domains appear near the top
left corner of the output table. Remember that the <a href="QSHAPE_README.html#active_queue">active queue</a>
can accommodate up to 20000 ($<a href="postconf.5.html#qmgr_message_active_limit">qmgr_message_active_limit</a>) messages.
-To check wether this limit has been reached, use: </p>
+To check whether this limit has been reached, use: </p>
<blockquote>
<pre>
-$ qshape -s active | head <i>(show sender statistics)</i>
+$ qshape -s active <i>(show sender statistics)</i>
</pre>
</blockquote>
not yet saturated, any high volume sender domains show near the
top of the output.
-<p> The <a href="QSHAPE_README.html#active_queue">active queue</a> is also limited to at most 20000 recipient
-addresses ($<a href="postconf.5.html#qmgr_message_recipient_limit">qmgr_message_recipient_limit</a>). To check for exhaustion
-of this limit use: </p>
+<p> With <a href="qmgr.8.html">oqmgr(8)</a> the <a href="QSHAPE_README.html#active_queue">active queue</a> is also limited to at most 20000
+recipient addresses ($<a href="postconf.5.html#qmgr_message_recipient_limit">qmgr_message_recipient_limit</a>). To check for
+exhaustion of this limit use: </p>
<blockquote>
<pre>
-$ qshape active | head <i>(show recipient statistics)</i>
+$ qshape active <i>(show recipient statistics)</i>
</pre>
</blockquote>
take measures to ensure that the mail is deferred instead or even
add an <a href="access.5.html">access(5)</a> rule asking the sender to try again later. </p>
-<p> If a high volume destination exhibits frequent bursts of
-consecutive connections refused by all MX hosts or "421 Server busy
-errors", it is possible for the queue manager to mark the destination
-as "dead" despite the transient nature of the errors. The destination
-will be retried again after the expiration of a $<a href="postconf.5.html#minimal_backoff_time">minimal_backoff_time</a>
-timer. If the error bursts are frequent enough it may be that only
-a small quantity of email is delivered before the destination is
-again marked "dead". </p>
+<p> If a high volume destination exhibits frequent bursts of consecutive
+connections refused by all MX hosts or "421 Server busy errors", it
+is possible for the queue manager to mark the destination as "dead"
+despite the transient nature of the errors. The destination will be
+retried again after the expiration of a $<a href="postconf.5.html#minimal_backoff_time">minimal_backoff_time</a> timer.
+If the error bursts are frequent enough it may be that only a small
+quantity of email is delivered before the destination is again marked
+"dead". In some cases enabling static (not on demand) connection
+caching by listing the appropriate nexthop domain in a table included in
+"<a href="postconf.5.html#smtp_connection_cache_destinations">smtp_connection_cache_destinations</a>" may help to reduce the error rate,
+because most messages will re-use existing connections. </p>
<p> The MTA that has been observed most frequently to exhibit such
bursts of errors is Microsoft Exchange, which refuses connections
server propagate the refused connection to the client as a "421"
error. </p>
-<p> Note that it is now possible to configure Postfix to exhibit
-similarly erratic behavior by misconfiguring the <a href="anvil.8.html">anvil(8)</a> server
-(not included in Postfix 2.1.). Do not use <a href="anvil.8.html">anvil(8)</a> for steady-state
-rate limiting, its purpose is DoS prevention and the rate limits
-set should be very generous! </p>
+<p> Note that it is now possible to configure Postfix to exhibit similarly
+erratic behavior by misconfiguring the <a href="anvil.8.html">anvil(8)</a> service. Do not use
+<a href="anvil.8.html">anvil(8)</a> for steady-state rate limiting, its purpose is (unintentional)
+DoS prevention and the rate limits set should be very generous! </p>
-<p> In the long run it is hoped that the Postfix dead host detection
-and concurrency control mechanism will be tuned to be more "noise"
-tolerant. If one finds oneself needing to deliver a high volume
-of mail to a destination that exhibits frequent brief bursts of
-errors, there is a subtle workaround. </p>
+<p> If one finds oneself needing to deliver a high volume of mail to a
+destination that exhibits frequent brief bursts of errors and connection
+caching does not solve the problem, there is a subtle workaround. </p>
<ul>
-<li> <p> In master.cf set up a dedicated clone of the "smtp"
+<li> <p> In <a href="master.5.html">master.cf</a> set up a dedicated clone of the "smtp"
transport for the destination in question. </p>
-<li> <p> In master.cf configure a reasonable process limit for the
+<li> <p> In <a href="master.5.html">master.cf</a> configure a reasonable process limit for the
transport (a number in the 10-20 range is typical). </p>
-<li> <p> IMPORTANT!!! In main.cf configure a very large initial
-and destination concurrency limit for this transport (say 200). </p>
+<li> <p> IMPORTANT!!! In <a href="postconf.5.html">main.cf</a> configure a very large initial
+and destination concurrency limit for this transport (say 2000). </p>
<pre>
-/etc/postfix/main.cf:
- <a href="postconf.5.html#initial_destination_concurrency">initial_destination_concurrency</a> = 200
- <i>transportname</i>_destination_concurrency_limit = 200
+/etc/postfix/<a href="postconf.5.html">main.cf</a>:
+ <a href="postconf.5.html#initial_destination_concurrency">initial_destination_concurrency</a> = 2000
+ <i>transportname</i>_destination_concurrency_limit = 2000
</pre>
-<p> Where <i>transportname</i> is the name of the master.cf entry
+<p> Where <i>transportname</i> is the name of the <a href="master.5.html">master.cf</a> entry
in question. </p>
</ul>
-<p> The effect of this surprising configuration is that up to 200
+<p> The effect of this surprising configuration is that up to 2000
consecutive errors are tolerated without marking the destination
dead, while the total concurrency remains reasonable (10-20
processes). This trick is only for a very specialized situation:
high volume delivery into a channel with multi-error bursts
that is capable of high throughput, but is repeatedly throttled by
-the bursts of errors.
+the bursts of errors. </p>
<p> When a destination is unable to handle the load even after the
Postfix process limit is reduced to 1, a desperate measure is to
<li> <p> In the transport map entry for the problem destination,
specify a dead host as the primary nexthop. </p>
-<li> <p> In the master.cf entry for the transport specify the
+<li> <p> In the <a href="master.5.html">master.cf</a> entry for the transport specify the
problem destination as the <a href="postconf.5.html#fallback_relay">fallback_relay</a> and specify a small
<a href="postconf.5.html#smtp_connect_timeout">smtp_connect_timeout</a> value. </p>
/etc/postfix/transport:
problem.example.com slow:[dead.host]
-/etc/postfix/master.cf:
+/etc/postfix/<a href="master.5.html">master.cf</a>:
# service type private unpriv chroot wakeup maxproc command
slow unix - - n - 1 smtp
-o <a href="postconf.5.html#fallback_relay">fallback_relay</a>=problem.example.com
<p> Hopefully a more elegant solution to these problems will be
found in the future. </p>
-<h2><a name="queues">Background info: Postfix queue directories</a></h2>
+<h2><a name="queues">Postfix queue directories</a></h2>
<p> The following sections describe Postfix queues: their purpose,
what normal behavior looks like, and how to diagnose abnormal
<p> All mail that enters the main Postfix queue does so via the
<a href="cleanup.8.html">cleanup(8)</a> service. The cleanup service is responsible for envelope
and header rewriting, header and body regular expression checks,
-automatic bcc recipient processing and guaranteed insertion of the
-message into the Postfix "<a href="QSHAPE_README.html#incoming_queue">incoming" queue</a>. </p>
+automatic bcc recipient processing, milter content processing, and
+
reliable insertion of the message into the Postfix "<a href="QSHAPE_README.html#incoming_queue">incoming" queue</a>. </p>
<p> In the absence of excessive CPU consumption in <a href="cleanup.8.html">cleanup(8)</a> header
or body regular expression checks or other software consuming all
disk I/O latency (+ CPU if not negligible) of the cleanup service.
</p>
-<p> Congestion in this queue is indicative of an excessive local
-message submission rate or perhaps excessive CPU consumption in
-the <a href="cleanup.8.html">cleanup(8)</a> service due to excessive <a href="postconf.5.html#body_checks">body_checks</a>. </p>
+<p> Congestion in this queue is indicative of an excessive local message
+submission rate or perhaps excessive CPU consumption in the <a href="cleanup.8.html">cleanup(8)</a>
+service due to excessive <a href="postconf.5.html#body_checks">body_checks</a>, or (Postfix ≥ 2.3) high latency
+milters. </p>
<p> Note, that once the <a href="QSHAPE_README.html#active_queue">active queue</a> is full, the cleanup service
will attempt to slow down message injection by pausing $<a href="postconf.5.html#in_flow_delay">in_flow_delay</a>
a consequence of congestion downstream, rather than a problem in
its own right. </p>
-<p> Note also, that one should not attempt to deliver large volumes
-of mail via the <a href="pickup.8.html">pickup(8)</a> service. High volume sites must avoid
-using content filters that reinject scanned mail via Postfix
-
<a href="sendmail.1.html">sendmail(1)</a> and <a href="postdrop.1.html">postdrop(1)</a>. </p>
+<p> Note, you should not attempt to deliver large volumes of mail via
+the <a href="pickup.8.html">pickup(8)</a> service. High volume sites should avoid using "simple"
+content filters that re-inject scanned mail via Postfix <a href="sendmail.1.html">sendmail(1)</a>
+and <a href="postdrop.1.html">postdrop(1)</a>. </p>
<p> A high arrival rate of locally submitted mail may be an indication
of an uncaught forwarding loop, or a run-away notification program.
<p> The administrator can define "smtpd" <a href="access.5.html">access(5)</a> policies, or
<a href="cleanup.8.html">cleanup(8)</a> header/body checks that cause messages to be automatically
diverted from normal processing and placed indefinitely in the
-"<a href="QSHAPE_README.html#hold_queue">hold" queue</a>. Messages placed in the "hold" queue stay there until
+"<a href="QSHAPE_README.html#hold_queue">hold" queue</a>. Messages placed in the "hold" queue stay there until
the administrator intervenes. No periodic delivery attempts are
made for messages in the "<a href="QSHAPE_README.html#hold_queue">hold" queue</a>. The <a href="postsuper.1.html">postsuper(1)</a> command
can be used to manually release messages into the "<a href="QSHAPE_README.html#deferred_queue">deferred" queue</a>.
</p>
-<p> Messages can potentially stay in the "<a href="QSHAPE_README.html#hold_queue">hold" queue</a> for a time
-exceeding the normal maximal queue lifetime (after which undelivered
-messages are bounced back to the sender). If such "old" messages
-need to be released from the "<a href="QSHAPE_README.html#hold_queue">hold" queue</a>, they should typically
-be moved into the "<a href="QSHAPE_README.html#maildrop_queue">maildrop" queue</a>, so that the message gets a new
-timestamp and is given more than one opportunity to be delivered.
-Messages that are "young" can be moved directly into the "deferred"
-queue. </p>
+<p> Messages can potentially stay in the "<a href="QSHAPE_README.html#hold_queue">hold" queue</a> longer than
+$<a href="postconf.5.html#maximal_queue_lifetime">maximal_queue_lifetime</a>. If such "old" messages need to be released from
+the "<a href="QSHAPE_README.html#hold_queue">hold" queue</a>, they should typically be moved into the "maildrop"
+queue using "postsuper -r", so that the message gets a new timestamp and
+is given more than one opportunity to be delivered. Messages that are
+"young" can be moved directly into the "<a href="QSHAPE_README.html#deferred_queue">deferred" queue</a> using
+"postsuper -H". </p>
<p> The "<a href="QSHAPE_README.html#hold_queue">hold" queue</a> plays little role in Postfix performance, and
monitoring of the "<a href="QSHAPE_README.html#hold_queue">hold" queue</a> is typically more closely motivated
<p> The <a href="QSHAPE_README.html#incoming_queue">incoming queue</a> grows when the message input rate spikes
above the rate at which the queue manager can import messages into
-the <a href="QSHAPE_README.html#active_queue">active queue</a>. The main factor slowing down the queue manager
-is transport queries to the trivial-rewrite service. If the queue
+the <a href="QSHAPE_README.html#active_queue">active queue</a>. The main factors slowing down the queue manager
+are disk I/O and lookup queries to the trivial-rewrite service. If the queue
manager is routinely not keeping up, consider not using "slow"
lookup services (MySQL, LDAP, ...) for transport lookups or speeding
-up the hosts that provide the lookup service. </p>
+up the hosts that provide the lookup service. If the problem is I/O
+starvation, consider striping the queue over more disks, faster controllers
+with a battery write cache, or other hardware improvements. At the very
+least, make sure that the queue directory is mounted with the "noatime"
+option if applicable to the underlying filesystem. </p>
<p> The <a href="postconf.5.html#in_flow_delay">in_flow_delay</a> parameter is used to clamp the input rate
when the queue manager starts to fall behind. The <a href="cleanup.8.html">cleanup(8)</a> service
concurrency limit. </p>
<p> Multiple recipient groups (from one or more messages) are queued
-for delivery via the common transport/nexthop combination. The
-destination concurrency limit for the transports caps the number
+for delivery grouped by transport/nexthop combination. The
+<b>destination</b> concurrency limit for the transports caps the number
of simultaneous delivery attempts for each nexthop. Transports with
-a recipient concurrency limit of 1 are special: these are grouped
-by the actual recipient address rather than the nexthop, thereby
-enabling per-recipient concurrency limits rather than per-domain
+a <b>recipient</b> concurrency limit of 1 are special: these are grouped
+by the actual recipient address rather than the nexthop, yielding
+per-recipient concurrency limits rather than per-domain
concurrency limits. Per-recipient limits are appropriate when
performing final delivery to mailboxes rather than when relaying
to a remote server. </p>
<p> Congestion occurs in the <a href="QSHAPE_README.html#active_queue">active queue</a> when one or more destinations
-drain slower than the corresponding message input rate. If a
-destination is down for some time, the queue manager will mark it
-dead, and immediately defer all mail for the destination without
+drain slower than the corresponding message input rate. </p>
+
+<p> Input into the <a href="QSHAPE_README.html#active_queue">active queue</a> comes both from new mail in the "incoming"
+queue, and retries of mail in the "<a href="QSHAPE_README.html#deferred_queue">deferred" queue</a>. Should the "deferred"
+queue get really large, retries of old mail can dominate the arrival
+rate of new mail. Systems with more CPU, faster disks and more network
+bandwidth can deal with larger <a href="QSHAPE_README.html#deferred_queue">deferred queues</a>, but as a rule of thumb
+the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> scales to somewhere between 100,000 and 1,000,000
+messages with good performance unlikely above that "limit". Systems with
+queues this large should typically stop accepting new mail, or put the
+backlog "on hold" until the underlying issue is fixed (provided that
+there is enough capacity to handle just the new mail). </p>
+
+<p> When a destination is down for some time, the queue manager will
+mark it dead, and immediately defer all mail for the destination without
trying to assign it to a delivery agent. In this case the messages
-will quickly leave the <a href="QSHAPE_README.html#active_queue">active queue</a> and end up in the deferred
-queue. If the destination is instead simply slow, or there is a
-problem causing an excessive arrival rate the <a href="QSHAPE_README.html#active_queue">active queue</a> will
-grow and will become dominated by mail to the congested destination.
-</p>
+will quickly leave the <a href="QSHAPE_README.html#active_queue">active queue</a> and end up in the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a>
+(with Postfix < 2.4, this is done directly by the queue manager,
+with Postfix ≥ 2.4 this is done via the "retry" delivery agent). </p>
+
+<p> When the destination is instead simply slow, or there is a problem
+causing an excessive arrival rate the <a href="QSHAPE_README.html#active_queue">active queue</a> will grow and will
+become dominated by mail to the congested destination. </p>
<p> The only way to reduce congestion is to either reduce the input
rate or increase the throughput. Increasing the throughput requires
is draining slowly and the system and network are not loaded, raise
the "smtp" and/or "relay" process limits! </p>
-<p> Especially for the "relay" transport, consider lower SMTP
-connection timeouts (1-5 seconds) and higher than default destination
-concurrency limits. Compute the expected latency when 1 out of N
-of the MX hosts for a high volume site is down and not responding,
-and make sure that the configured concurrency divided by this
-latency exceeds the required steady-state message rate. If the
-destination is managed by you, consider load balancers in front of
-groups of MX hosts. Load balancers have higher uptime and will be
-able to hide individual MX host failures. </p>
-
-<p> If necessary, dedicate and tune custom transports for high
-volume destinations. </p>
-
-<p> Another common cause of congestion is unwarranted flushing of
-the entire <a href="QSHAPE_README.html#deferred_queue">deferred queue</a>. The deferred queue holds messages that
-are likely to fail to be delivered and are also likely to be slow
-to fail delivery (timeouts). This means that the most common reaction
-to a large <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> (flush it!) is more than likely counter-
-productive, and is likely to make the problem worse. Do not flush
-the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> unless you expect that most of its content has
-recently become deliverable (e.g. <a href="postconf.5.html#relayhost">relayhost</a> back up after an outage)!
-</p>
+<p> When a high volume destination is served by multiple MX hosts with
+typically low delivery latency, performance can suffer dramatically when
+one of the MX hosts is unresponsive and SMTP connections to that host
+timeout. For example, if there are 2 equal weight MX hosts, the SMTP
+connection timeout is 30 seconds and one of the MX hosts is down, the
+average SMTP connection will take approximately 15 seconds to complete.
+With a default per-destination concurrency limit of 20 connections,
+throughput falls to just over 1 message per second. </p>
+
+<p> The best way to avoid bottlenecks when one or more MX hosts is
+non-responsive is to use connection caching. Connection caching was
+introduced with Postfix 2.2 and is by default enabled on demand for
+destinations with a backlog of mail in the <a href="QSHAPE_README.html#active_queue">active queue</a>. When connection
+caching is in effect for a particular destination, established connections
+are re-used to send additional messages, this reduces the number of
+connections made per message delivery and maintains good throughput even
+in the face of partial unavailability of the destination's MX hosts. </p>
+
+<p> If connection caching is not available (Postfix < 2.2) or does
+not provide a sufficient latency reduction, especially for the "relay"
+transport used to forward mail to "your own" domains, consider setting
+lower than default SMTP connection timeouts (1-5 seconds) and higher
+than default destination concurrency limits. This will further reduce
+latency and provide more concurrency to maintain throughput should
+latency rise. </p>
+
+<p> Setting high concurrency limits to domains that are not your own may
+be viewed as hostile by the receiving system, and steps may be taken
+to prevent you from monopolizing the destination system's resources.
+The defensive measures may substantially reduce your throughput or block
+access entirely. Do not set aggressive concurrency limits to remote
+domains without coordinating with the administrators of the target
+domain. </p>
+
+<p> If necessary, dedicate and tune custom transports for selected high
+volume destinations. The "relay" transport is provided for forwarding mail
+to domains for which your server is a primary or backup MX host. These can
+make up a substantial fraction of your email traffic. Use the "relay" and
+not the "smtp" transport to send email to these domains. Using the "relay"
+transport allocates a separate delivery agent pool to these destinations
+and allows separate tuning of timeouts and concurrency limits. </p>
+
+<p> Another common cause of congestion is unwarranted flushing of the
+entire <a href="QSHAPE_README.html#deferred_queue">deferred queue</a>. The deferred queue holds messages that are likely
+to fail to be delivered and are also likely to be slow to fail delivery
+(time out). As a result the most common reaction to a large <a href="QSHAPE_README.html#deferred_queue">deferred queue</a>
+(flush it!) is more than likely counter-productive, and typically makes
+the congestion worse. Do not flush the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> unless you expect
+that most of its content has recently become deliverable (e.g. <a href="postconf.5.html#relayhost">relayhost</a>
+back up after an outage)! </p>
<p> Note that whenever the queue manager is restarted, there may
already be messages in the <a href="QSHAPE_README.html#active_queue">active queue</a> directory, but the "real"
the messages back and forth, redoing transport table (<a href="trivial-rewrite.8.html">trivial-rewrite(8)</a>
resolve service) lookups, and re-importing the messages back into
memory is expensive. At all costs, avoid frequent restarts of the
-queue manager. </p>
+queue manager (e.g. via frequent execution of "postfix reload"). </p>
<h3> <a name="deferred_queue"> The "deferred" queue </a> </h3>
might succeed later), the message is placed in the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a>.
</p>
-<p> The queue manager scans the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> periodically. The
-scan interval is controlled by the <a href="postconf.5.html#queue_run_delay">queue_run_delay</a> parameter.
-While a <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> scan is in progress, if an <a href="QSHAPE_README.html#incoming_queue">incoming queue</a>
-scan is also in progress (ideally these are brief since the incoming
-queue should be short), the queue manager alternates between bringing
-a new "incoming" message and a new "deferred" message into the
-queue. This "round-robin" strategy prevents starvation of either
-the <a href="QSHAPE_README.html#incoming_queue">incoming</a> or the <a href="QSHAPE_README.html#deferred_queue">deferred queues</a>. </p>
+<p> The queue manager scans the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> periodically. The scan
+interval is controlled by the <a href="postconf.5.html#queue_run_delay">queue_run_delay</a> parameter. While a deferred
+queue scan is in progress, if an <a href="QSHAPE_README.html#incoming_queue">incoming queue</a> scan is also in progress
+(ideally these are brief since the <a href="QSHAPE_README.html#incoming_queue">incoming queue</a> should be short), the
+queue manager alternates between looking for messages in the "incoming"
+queue and in the "<a href="QSHAPE_README.html#deferred_queue">deferred" queue</a>. This "round-robin" strategy prevents
+starvation of either the <a href="QSHAPE_README.html#incoming_queue">incoming</a> or the <a href="QSHAPE_README.html#deferred_queue">deferred queues</a>. </p>
<p> Each <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> scan only brings a fraction of the deferred
queue back into the <a href="QSHAPE_README.html#active_queue">active queue</a> for a retry. This is because each
message in the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> is assigned a "cool-off" time when
it is deferred. This is done by time-warping the modification
-times of the queue file into the future. The queue file is not
+time of the queue file into the future. The queue file is not
eligible for a retry if its modification time is not yet reached.
</p>
retried more often than old messages. </p>
<p> If a high volume site routinely has large <a href="QSHAPE_README.html#deferred_queue">deferred queues</a>, it
-may be useful to adjust the <a href="postconf.5.html#queue_run_delay">queue_run_delay</a>, <a href="postconf.5.html#minimal_backoff_time">minimal_backoff_time</a>
-and <a href="postconf.5.html#maximal_backoff_time">maximal_backoff_time</a> to provide short enough delays on first
-failure, with perhaps longer delays after multiple failures, to
-reduce the retransmission rate of old messages and thereby reduce
-the quantity of previously deferred mail in the <a href="QSHAPE_README.html#active_queue">active queue</a>. </p>
+may be useful to adjust the <a href="postconf.5.html#queue_run_delay">queue_run_delay</a>, <a href="postconf.5.html#minimal_backoff_time">minimal_backoff_time</a> and
+<a href="postconf.5.html#maximal_backoff_time">maximal_backoff_time</a> to provide short enough delays on first failure
+(Postfix ≥ 2.4 has a sensibly low minimal backoff time by default),
+with perhaps longer delays after multiple failures, to reduce the
+retransmission rate of old messages and thereby reduce the quantity
+of previously deferred mail in the <a href="QSHAPE_README.html#active_queue">active queue</a>. If you want a really
+low <a href="postconf.5.html#minimal_backoff_time">minimal_backoff_time</a>, you may also want to lower <a href="postconf.5.html#queue_run_delay">queue_run_delay</a>,
+but understand that more frequent scans will increase the demand for
+disk I/O. </p>
<p> One common cause of large <a href="QSHAPE_README.html#deferred_queue">deferred queues</a> is failure to validate
recipients at the SMTP input stage. Since spammers routinely launch
dictionary attacks from unrepliable sender addresses, the bounces
-for invalid recipient addresses clog the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> (and at
-high volumes proportionally clog the <a href="QSHAPE_README.html#active_queue">active queue</a>). Recipient
-validation is strongly recommended through use of the <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a>
-and <a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> parameters. </p>
+for invalid recipient addresses clog the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> (and at high
+volumes proportionally clog the <a href="QSHAPE_README.html#active_queue">active queue</a>). Recipient validation
+is strongly recommended through use of the <a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> and
+<a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> parameters. Even when bounces drain quickly they
+inundate innocent victims of forgery with unwanted email. To avoid
+this, do not accept mail for invalid recipients. </p>
<p> When a host with lots of deferred mail is down for some time,
it is possible for the entire <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> to reach its retry
time simultaneously. This can lead to a very full <a href="QSHAPE_README.html#active_queue">active queue</a> once
the host comes back up. The phenomenon can repeat approximately
every <a href="postconf.5.html#maximal_backoff_time">maximal_backoff_time</a> seconds if the messages are again deferred
-after a brief burst of congestion. Ideally, in the future Postfix
+after a brief burst of congestion. Perhaps, a future Postfix release
will add a random offset to the retry time (or use a combination
-of strategies) to reduce the chances of repeated complete deferred
+of strategies) to reduce the odds of repeated complete deferred
queue flushes. </p>
<h2><a name="credits">Credits</a></h2>
ACCESS(5) ACCESS(5)
<b>NAME</b>
- access - Postfix access table format
+ access - Postfix SMTP server access table
<b>SYNOPSIS</b>
<b>postmap /etc/postfix/access</b>
<b>postmap -q - /etc/postfix/access</b> <<i>inputfile</i>
<b>DESCRIPTION</b>
- The optional <a href="access.5.html"><b>access</b>(5)</a> table directs the Postfix SMTP
- server to selectively reject or accept mail. Access can be
- allowed or denied for specific host names, domain names,
- networks, host addresses or mail addresses.
-
- For an example, see the EXAMPLE section at the end of this
- manual page.
-
- Normally, the <a href="access.5.html"><b>access</b>(5)</a> table is specified as a text file
- that serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command. The
- result, an indexed file in <b>dbm</b> or <b>db</b> format, is used for
- fast searching by the mail system. Execute the command
- "<b>postmap /etc/postfix/access</b>" in order to rebuild the
- indexed file after changing the access table.
-
- When the table is provided via other means such as NIS,
- LDAP or SQL, the same lookups are done as for ordinary
+ The Postfix SMTP server <a href="access.5.html"><b>access</b>(5)</a> table specifies actions
+ that are triggered by information from or about remote
+ SMTP clients: host names, network addresses, or email
+ addresses. An action may grant or deny access, or it may
+ change the way that an email transaction will be handled.
+
+ Normally, the <a href="access.5.html"><b>access</b>(5)</a> table is specified as a text file
+ that serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command. The
+ result, an indexed file in <b>dbm</b> or <b>db</b> format, is used for
+ fast searching by the mail system. Execute the command
+ "<b>postmap /etc/postfix/access</b>" to rebuild an indexed file
+ after changing the corresponding text file.
+
+ When the table is provided via other means such as NIS,
+ LDAP or SQL, the same lookups are done as for ordinary
indexed files.
- Alternatively, the table can be provided as a regular-
+ Alternatively, the table can be provided as a regular-
expression map where patterns are given as regular expres-
- sions, or lookups can be directed to TCP-based server. In
- that case, the lookups are done in a slightly different
- way as described below under "REGULAR EXPRESSION TABLES"
- and "TCP-BASED TABLES".
+ sions, or lookups can be directed to TCP-based server. In
+ those cases, the lookups are done in a slightly different
+ way as described below under "REGULAR EXPRESSION TABLES"
+ or "TCP-BASED TABLES".
<b>CASE FOLDING</b>
- The search string is folded to lowercase before database
- lookup. As of Postfix 2.3, the search string is not case
- folded with database types such as <a href="regexp_table.5.html">regexp</a>: or <a href="pcre_table.5.html">pcre</a>: whose
+ The search string is folded to lowercase before database
+ lookup. As of Postfix 2.3, the search string is not case
+ folded with database types such as <a href="regexp_table.5.html">regexp</a>: or <a href="pcre_table.5.html">pcre</a>: whose
lookup fields can match both upper and lower case.
<b>TABLE FORMAT</b>
address, perform the corresponding <i>action</i>.
blank lines and comments
- Empty lines and whitespace-only lines are ignored,
- as are lines whose first non-whitespace character
+ Empty lines and whitespace-only lines are ignored,
+ as are lines whose first non-whitespace character
is a `#'.
multi-line text
- A logical line starts with non-whitespace text. A
- line that starts with whitespace continues a logi-
+ A logical line starts with non-whitespace text. A
+ line that starts with whitespace continues a logi-
cal line.
<b>EMAIL ADDRESS PATTERNS</b>
With lookups from indexed files such as DB or DBM, or from
- networked tables such as NIS, LDAP or SQL, patterns are
+ networked tables such as NIS, LDAP or SQL, patterns are
tried in the order as listed below:
<i>user</i>@<i>domain</i>
Matches the specified mail address.
<i>domain.tld</i>
- Matches <i>domain.tld</i> as the domain part of an email
+ Matches <i>domain.tld</i> as the domain part of an email
address.
The pattern <i>domain.tld</i> also matches subdomains, but
only when the string <b>smtpd_access_maps</b> is listed in
- the Postfix <b><a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a></b> con-
- figuration setting (note that this is the default
- for some versions of Postfix). Otherwise, specify
- <i>.domain.tld</i> (note the initial dot) in order to
+ the Postfix <b><a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a></b> con-
+ figuration setting (note that this is the default
+ for some versions of Postfix). Otherwise, specify
+ <i>.domain.tld</i> (note the initial dot) in order to
match subdomains.
- <i>user</i>@ Matches all mail addresses with the specified user
+ <i>user</i>@ Matches all mail addresses with the specified user
part.
- Note: lookup of the null sender address is not possible
- with some types of lookup table. By default, Postfix uses
- <> as the lookup key for such addresses. The value is
- specified with the <b><a href="postconf.5.html#smtpd_null_access_lookup_key">smtpd_null_access_lookup_key</a></b> parameter
+ Note: lookup of the null sender address is not possible
+ with some types of lookup table. By default, Postfix uses
+ <> as the lookup key for such addresses. The value is
+ specified with the <b><a href="postconf.5.html#smtpd_null_access_lookup_key">smtpd_null_access_lookup_key</a></b> parameter
in the Postfix <a href="postconf.5.html"><b>main.cf</b></a> file.
<b>EMAIL ADDRESS EXTENSION</b>
When a mail address localpart contains the optional recip-
- ient delimiter (e.g., <i>user+foo</i>@<i>domain</i>), the lookup order
- becomes: <i>user+foo</i>@<i>domain</i>, <i>user</i>@<i>domain</i>, <i>domain</i>, <i>user+foo</i>@,
+ ient delimiter (e.g., <i>user+foo</i>@<i>domain</i>), the lookup order
+ becomes: <i>user+foo</i>@<i>domain</i>, <i>user</i>@<i>domain</i>, <i>domain</i>, <i>user+foo</i>@,
and <i>user</i>@.
<b>HOST NAME/ADDRESS PATTERNS</b>
With lookups from indexed files such as DB or DBM, or from
- networked tables such as NIS, LDAP or SQL, the following
+ networked tables such as NIS, LDAP or SQL, the following
lookup patterns are examined in the order as listed:
<i>domain.tld</i>
The pattern <i>domain.tld</i> also matches subdomains, but
only when the string <b>smtpd_access_maps</b> is listed in
- the Postfix <b><a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a></b> con-
+ the Postfix <b><a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a></b> con-
figuration setting. Otherwise, specify <i>.domain.tld</i>
- (note the initial dot) in order to match subdo-
+ (note the initial dot) in order to match subdo-
mains.
<i>net.work.addr.ess</i>
<i>net.work</i>
- <i>net</i> Matches the specified IPv4 host address or subnet-
- work. An IPv4 host address is a sequence of four
+ <i>net</i> Matches the specified IPv4 host address or subnet-
+ work. An IPv4 host address is a sequence of four
decimal octets separated by ".".
- Subnetworks are matched by repeatedly truncating
+ Subnetworks are matched by repeatedly truncating
the last ".octet" from the remote IPv4 host address
- string until a match is found in the access table,
+ string until a match is found in the access table,
or until further truncation is not possible.
NOTE 1: The information in the access map should be
in canonical form, with unnecessary null characters
- eliminated. Address information must not be
+ eliminated. Address information must not be
enclosed with "[]" characters.
- NOTE 2: use the <b>cidr</b> lookup table type to specify
+ NOTE 2: use the <b>cidr</b> lookup table type to specify
network/netmask patterns. See <a href="cidr_table.5.html"><b>cidr_table</b>(5)</a> for
details.
<i>net:work</i>
- <i>net</i> Matches the specified IPv6 host address or subnet-
- work. An IPv6 host address is a sequence of three
- to eight hexadecimal octet pairs separated by ":".
+ <i>net</i> Matches the specified IPv6 host address or subnet-
+ work. An IPv6 host address is a sequence of three
+ to eight hexadecimal octet pairs separated by ":".
- Subnetworks are matched by repeatedly truncating
- the last ":octetpair" from the remote IPv6 host
+ Subnetworks are matched by repeatedly truncating
+ the last ":octetpair" from the remote IPv6 host
address string until a match is found in the access
table, or until further truncation is not possible.
NOTE 2: The information in the access map should be
in canonical form, with unnecessary null characters
- eliminated. Address information must not be
+ eliminated. Address information must not be
enclosed with "[]" characters.
- NOTE 3: use the <b>cidr</b> lookup table type to specify
+ NOTE 3: use the <b>cidr</b> lookup table type to specify
network/netmask patterns. See <a href="cidr_table.5.html"><b>cidr_table</b>(5)</a> for
details.
<i>all-numerical</i>
An all-numerical result is treated as OK. This for-
- mat is generated by address-based relay authoriza-
+ mat is generated by address-based relay authoriza-
tion schemes such as pop-before-smtp.
<b>REJECT ACTIONS</b>
- Postfix version 2.3 and later support enhanced status
- codes as defined in <a href="http://www.faqs.org/rfcs/rfc3463.html">RFC 3463</a>. When no code is specified
- at the beginning of the <i>text</i> below, Postfix inserts a
- default enhanced status code of "5.7.1" in the case of
- reject actions, and "4.7.1" in the case of defer actions.
+ Postfix version 2.3 and later support enhanced status
+ codes as defined in <a href="http://www.faqs.org/rfcs/rfc3463.html">RFC 3463</a>. When no code is specified
+ at the beginning of the <i>text</i> below, Postfix inserts a
+ default enhanced status code of "5.7.1" in the case of
+ reject actions, and "4.7.1" in the case of defer actions.
See "ENHANCED STATUS CODES" below.
<b>4</b><i>NN text</i>
<b>5</b><i>NN text</i>
- Reject the address etc. that matches the pattern,
+ Reject the address etc. that matches the pattern,
and respond with the numerical three-digit code and
- text. <b>4</b><i>NN</i> means "try again later", while <b>5</b><i>NN</i> means
+ text. <b>4</b><i>NN</i> means "try again later", while <b>5</b><i>NN</i> means
"do not try again".
- The reply code "421" causes Postfix to disconnect
+ The reply code "421" causes Postfix to disconnect
immediately (Postfix version 2.3 and later).
<b>REJECT</b> <i>optional text...</i>
- Reject the address etc. that matches the pattern.
- Reply with <i>$reject</i><b>_</b><i>code optional text...</i> when the
- optional text is specified, otherwise reply with a
+ Reject the address etc. that matches the pattern.
+ Reply with <i>$reject</i><b>_</b><i>code optional text...</i> when the
+ optional text is specified, otherwise reply with a
generic error response message.
<b>DEFER_IF_REJECT</b> <i>optional text...</i>
- Defer the request if some later restriction would
+ Defer the request if some later restriction would
result in a REJECT action. Reply with "<b>450</b> <i>optional</i>
<i>text...</i> when the optional text is specified, other-
wise reply with a generic error response message.
This feature is available in Postfix 2.1 and later.
<b>DEFER_IF_PERMIT</b> <i>optional text...</i>
- Defer the request if some later restriction would
- result in a an explicit or implicit PERMIT action.
- Reply with "<b>450</b> <i>optional text...</i> when the optional
- text is specified, otherwise reply with a generic
+ Defer the request if some later restriction would
+ result in a an explicit or implicit PERMIT action.
+ Reply with "<b>450</b> <i>optional text...</i> when the optional
+ text is specified, otherwise reply with a generic
error response message.
This feature is available in Postfix 2.1 and later.
<b><a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a></b>, and so on).
<b>DISCARD</b> <i>optional text...</i>
- Claim successful delivery and silently discard the
- message. Log the optional text if specified, oth-
+ Claim successful delivery and silently discard the
+ message. Log the optional text if specified, oth-
erwise log a generic message.
- Note: this action currently affects all recipients
- of the message. To discard only one recipient
- without discarding the entire message, use the
+ Note: this action currently affects all recipients
+ of the message. To discard only one recipient
+ without discarding the entire message, use the
<a href="transport.5.html">transport(5)</a> table to direct mail to the <a href="discard.8.html">discard(8)</a>
service.
This feature is available in Postfix 2.0 and later.
- <b>DUNNO</b> Pretend that the lookup key was not found. This
- prevents Postfix from trying substrings of the
- lookup key (such as a subdomain name, or a network
+ <b>DUNNO</b> Pretend that the lookup key was not found. This
+ prevents Postfix from trying substrings of the
+ lookup key (such as a subdomain name, or a network
address subnetwork).
This feature is available in Postfix 2.0 and later.
<b>FILTER</b> <i>transport:destination</i>
- After the message is queued, send the entire mes-
+ After the message is queued, send the entire mes-
sage through the specified external content filter.
- The <i>transport:destination</i> syntax is described in
- the <a href="transport.5.html"><b>transport</b>(5)</a> manual page. More information
- about external content filters is in the Postfix
+ The <i>transport:destination</i> syntax is described in
+ the <a href="transport.5.html"><b>transport</b>(5)</a> manual page. More information
+ about external content filters is in the Postfix
<a href="FILTER_README.html">FILTER_README</a> file.
- Note:
this action overrides the <a href="postconf.5.html"><b>main.cf</a> <a href="postconf.5.html#content_filter">con</a>-</b>
+ Note:
this action overrides the <a href="postconf.5.html"><b>main.cf</a> <a href="postconf.5.html#content_filter">con</a>-</b>
<b><a href="postconf.5.html#content_filter">tent_filter</a></b> setting, and currently affects all
recipients of the message.
This feature is available in Postfix 2.0 and later.
<b>HOLD</b> <i>optional text...</i>
- Place the message on the <b>hold</b> queue, where it will
- sit until someone either deletes it or releases it
- for delivery. Log the optional text if specified,
+ Place the message on the <b>hold</b> queue, where it will
+ sit until someone either deletes it or releases it
+ for delivery. Log the optional text if specified,
otherwise log a generic message.
- Mail that is placed on hold can be examined with
- the <a href="postcat.1.html"><b>postcat</b>(1)</a> command, and can be destroyed or
+ Mail that is placed on hold can be examined with
+ the <a href="postcat.1.html"><b>postcat</b>(1)</a> command, and can be destroyed or
released with the <a href="postsuper.1.html"><b>postsuper</b>(1)</a> command.
- Note: use "<b>postsuper -r</b>" to release mail that was
- kept
on hold for a significant fraction of <b>$<a href="postconf.5.html#maximal_queue_lifetime">maxi</a>-</b>
+ Note: use "<b>postsuper -r</b>" to release mail that was
+ kept
on hold for a significant fraction of <b>$<a href="postconf.5.html#maximal_queue_lifetime">maxi</a>-</b>
<b><a href="postconf.5.html#maximal_queue_lifetime">mal_queue_lifetime</a></b> or <b>$<a href="postconf.5.html#bounce_queue_lifetime">bounce_queue_lifetime</a></b>, or
longer.
- Note: this action currently affects all recipients
+ Note: this action currently affects all recipients
of the message.
This feature is available in Postfix 2.0 and later.
<b>PREPEND</b> <i>headername: headervalue</i>
- Prepend the specified message header to the mes-
- sage. When this action is used multiple times, the
- first prepended header appears before the second
- etc. prepended header.
+ Prepend the specified message header to the mes-
+ sage. When this action executes multiple times,
+ the first prepended header appears before the sec-
+ ond etc. prepended header.
- Note: this action does not support multi-line mes-
+ Note: this action does not support multi-line mes-
sage headers.
- Note: this action must be used before the message
- content is received; it cannot be used in
- <b><a href="postconf.5.html#smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a></b>.
+ Note: this action must execute before the message
+ content is received; it cannot execute in the con-
+
text of <b><a href="postconf.5.html#smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a></b>.
This feature is available in Postfix 2.1 and later.
<b>REDIRECT</b> <i>user@domain</i>
- After the message is queued, send the message to
+ After the message is queued, send the message to
the specified address instead of the intended
recipient(s).
- Note: this action overrides the FILTER action, and
+ Note: this action overrides the FILTER action, and
currently affects all recipients of the message.
This feature is available in Postfix 2.1 and later.
<b>WARN</b> <i>optional text...</i>
Log a warning with the optional text, together with
- client information and if available, with helo,
+ client information and if available, with helo,
sender, recipient and protocol information.
This feature is available in Postfix 2.1 and later.
<b>ENHANCED STATUS CODES</b>
- Postfix version 2.3 and later support enhanced status
- codes as defined in <a href="http://www.faqs.org/rfcs/rfc3463.html">RFC 3463</a>. When an enhanced status
- code is specified in an access table, it is subject to
- modification. The following transformations are needed
- when the same access table is used for client, helo,
- sender, or recipient access restrictions; they happen
+ Postfix version 2.3 and later support enhanced status
+ codes as defined in <a href="http://www.faqs.org/rfcs/rfc3463.html">RFC 3463</a>. When an enhanced status
+ code is specified in an access table, it is subject to
+ modification. The following transformations are needed
+ when the same access table is used for client, helo,
+ sender, or recipient access restrictions; they happen
regardless of whether Postfix replies to a MAIL FROM, RCPT
TO or other SMTP command.
- <b>o</b> When a sender address matches a REJECT action, the
- Postfix SMTP server will transform a recipient DSN
- status (e.g., 4.1.1-4.1.6) into the corresponding
+ <b>o</b> When a sender address matches a REJECT action, the
+ Postfix SMTP server will transform a recipient DSN
+ status (e.g., 4.1.1-4.1.6) into the corresponding
sender DSN status, and vice versa.
- <b>o</b> When non-address information matches a REJECT
- action (such as the HELO command argument or the
- client hostname/address), the Postfix SMTP server
- will transform a sender or recipient DSN status
- into a generic non-address DSN status (e.g.,
+ <b>o</b> When non-address information matches a REJECT
+ action (such as the HELO command argument or the
+ client hostname/address), the Postfix SMTP server
+ will transform a sender or recipient DSN status
+ into a generic non-address DSN status (e.g.,
4.0.0).
<b>REGULAR EXPRESSION TABLES</b>
- This section describes how the table lookups change when
+ This section describes how the table lookups change when
the table is given in the form of regular expressions. For
- a description of regular expression lookup table syntax,
+ a description of regular expression lookup table syntax,
see <a href="regexp_table.5.html"><b>regexp_table</b>(5)</a> or <a href="pcre_table.5.html"><b>pcre_table</b>(5)</a>.
- Each pattern is a regular expression that is applied to
+ Each pattern is a regular expression that is applied to
the entire string being looked up. Depending on the appli-
- cation, that string is an entire client hostname, an
+ cation, that string is an entire client hostname, an
entire client IP address, or an entire mail address. Thus,
no parent domain or parent network search is done,
- <i>user@domain</i> mail addresses are not broken up into their
+ <i>user@domain</i> mail addresses are not broken up into their
<i>user@</i> and <i>domain</i> constituent parts, nor is <i>user+foo</i> broken
up into <i>user</i> and <i>foo</i>.
- Patterns are applied in the order as specified in the ta-
- ble, until a pattern is found that matches the search
+ Patterns are applied in the order as specified in the ta-
+ ble, until a pattern is found that matches the search
string.
- Actions are the same as with indexed file lookups, with
- the additional feature that parenthesized substrings from
+ Actions are the same as with indexed file lookups, with
+ the additional feature that parenthesized substrings from
the pattern can be interpolated as <b>$1</b>, <b>$2</b> and so on.
<b>TCP-BASED TABLES</b>
- This section describes how the table lookups change when
+ This section describes how the table lookups change when
lookups are directed to a TCP-based server. For a descrip-
tion of the TCP client/server lookup protocol, see <a href="tcp_table.5.html"><b>tcp_ta-</b></a>
<a href="tcp_table.5.html"><b>ble</b>(5)</a>. This feature is not available up to and including
Postfix version 2.4.
- Each lookup operation uses the entire query string once.
- Depending on the application, that string is an entire
+ Each lookup operation uses the entire query string once.
+ Depending on the application, that string is an entire
client hostname, an entire client IP address, or an entire
- mail address. Thus, no parent domain or parent network
- search is done, <i>user@domain</i> mail addresses are not broken
- up into their <i>user@</i> and <i>domain</i> constituent parts, nor is
+ mail address. Thus, no parent domain or parent network
+ search is done, <i>user@domain</i> mail addresses are not broken
+ up into their <i>user@</i> and <i>domain</i> constituent parts, nor is
<i>user+foo</i> broken up into <i>user</i> and <i>foo</i>.
Actions are the same as with indexed file lookups.
<b>EXAMPLE</b>
- The following example uses an indexed file, so that the
- order of table entries does not matter. The example per-
- mits access by the client at address 1.2.3.4 but rejects
- all other clients in 1.2.3.0/24. Instead of <b>hash</b> lookup
- tables, some systems use <b>dbm</b>. Use the command "<b>postconf</b>
- <b>-m</b>" to find out what lookup tables Postfix supports on
+ The following example uses an indexed file, so that the
+ order of table entries does not matter. The example per-
+ mits access by the client at address 1.2.3.4 but rejects
+ all other clients in 1.2.3.0/24. Instead of <b>hash</b> lookup
+ tables, some systems use <b>dbm</b>. Use the command "<b>postconf</b>
+ <b>-m</b>" to find out what lookup tables Postfix supports on
your system.
/etc/postfix/<a href="postconf.5.html">main.cf</a>:
editing the file.
<b>BUGS</b>
- The table format does not understand quoting conventions.
+ The table format does not understand quoting conventions.
<b>SEE ALSO</b>
<a href="postmap.1.html">postmap(1)</a>, Postfix lookup table manager
<a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>SEE ALSO</b>
<a href="TUNING_README.html">TUNING_README</a>, performance tuning
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>HISTORY</b>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#notify_classes">notify_classes</a> (resource, software)</b>
- The list of error classes that are reported to the
+ The list of error classes that are reported to the
postmaster.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>FILES</b>
syslogd(8), system logging
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
file that serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command. The
result, an indexed file in <b>dbm</b> or <b>db</b> format, is used for
fast searching by the mail system. Execute the command
- "<b>postmap /etc/postfix/canonical</b>" in order to rebuild the
- indexed file after changing the text file.
+ "<b>postmap /etc/postfix/canonical</b>" to rebuild an indexed
+ file after changing the corresponding text file.
When the table is provided via other means such as NIS,
LDAP or SQL, the same lookups are done as for ordinary
Alternatively, the table can be provided as a regular-
expression map where patterns are given as regular expres-
sions, or lookups can be directed to TCP-based server. In
- that case, the lookups are done in a slightly different
+ those cases, the lookups are done in a slightly different
way as described below under "REGULAR EXPRESSION TABLES"
- and "TCP-BASED TABLES".
+ or "TCP-BASED TABLES".
By default the <a href="canonical.5.html"><b>canonical</b>(5)</a> mapping affects both message
header addresses (i.e. addresses that appear inside mes-
The Postfix mail system uses optional lookup tables.
These tables are usually in <b>dbm</b> or <b>db</b> format. Alterna-
tively, lookup tables can be specified in CIDR (Classless
- Inter-Domain Routing) form.
+ Inter-Domain Routing) form. In this case, each input is
+ compared against a list of patterns. When a match is
+ found, the corresponding result is returned and the search
+ is terminated.
- To find out what types of lookup tables your Postfix sys-
+ To find out what types of lookup tables your Postfix sys-
tem supports use the "<b>postconf -m</b>" command.
- To test lookup tables, use the "<b>postmap -q</b>" command as
+ To test lookup tables, use the "<b>postmap -q</b>" command as
described in the SYNOPSIS above.
<b>TABLE FORMAT</b>
The general form of a Postfix CIDR table is:
<i>network</i><b>_</b><i>address</i><b>/</b><i>network</i><b>_</b><i>mask result</i>
- When a search string matches the specified network
- block, use the corresponding <i>result</i> value. Specify
- 0.0.0.0/0 to match every IPv4 address, and ::/0 to
+ When a search string matches the specified network
+ block, use the corresponding <i>result</i> value. Specify
+ 0.0.0.0/0 to match every IPv4 address, and ::/0 to
match every IPv6 address.
An IPv4 network address is a sequence of four deci-
- mal octets separated by ".", and an IPv6 network
+ mal octets separated by ".", and an IPv6 network
address is a sequence of three to eight hexadecimal
octet pairs separated by ":".
- Before comparisons are made, lookup keys and table
+ Before comparisons are made, lookup keys and table
entries are converted from string to binary. There-
- fore table entries will be matched regardless of
+ fore table entries will be matched regardless of
redundant zero characters.
- Note: address information may be enclosed inside
+ Note: address information may be enclosed inside
"[]" but this form is not recommended.
IPv6 support is available in Postfix 2.2 and later.
<i>network</i><b>_</b><i>address result</i>
- When a search string matches the specified network
+ When a search string matches the specified network
address, use the corresponding <i>result</i> value.
blank lines and comments
- Empty lines and whitespace-only lines are ignored,
- as are lines whose first non-whitespace character
+ Empty lines and whitespace-only lines are ignored,
+ as are lines whose first non-whitespace character
is a `#'.
multi-line text
- A logical line starts with non-whitespace text. A
- line that starts with whitespace continues a logi-
+ A logical line starts with non-whitespace text. A
+ line that starts with whitespace continues a logi-
cal line.
<b>TABLE SEARCH ORDER</b>
- Patterns are applied in the order as specified in the ta-
- ble, until a pattern is found that matches the search
+ Patterns are applied in the order as specified in the ta-
+ ble, until a pattern is found that matches the search
string.
<b>EXAMPLE SMTPD ACCESS MAP</b>
- /etc/postfix/main.cf:
+ /etc/postfix/<a href="postconf.5.html">main.cf</a>:
<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> = ... <a href="cidr_table.5.html">cidr</a>:/etc/postfix/client.cidr ...
/etc/postfix/client.<a href="cidr_table.5.html">cidr</a>:
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#myhostname">myhostname</a> (see 'postconf -d' output)</b>
The internet hostname of this mail system.
<b><a href="postconf.5.html#myorigin">myorigin</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
The domain name that locally-posted mail appears to
- come from, and that locally posted mail is deliv-
+ come from, and that locally posted mail is deliv-
ered to.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#soft_bounce">soft_bounce</a> (no)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
Available in Postfix version 2.1 and later:
<b><a href="postconf.5.html#enable_original_recipient">enable_original_recipient</a> (yes)</b>
- Enable support for the X-Original-To message
+ Enable support for the X-Original-To message
header.
<b>FILES</b>
<a href="CONTENT_INSPECTION_README.html">CONTENT_INSPECTION_README</a> content inspection
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>SEE ALSO</b>
syslogd(8), system logging
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>HISTORY</b>
<b>DESCRIPTION</b>
The Postfix <a href="error.8.html"><b>error</b>(8)</a> delivery agent processes delivery
requests from the queue manager. Each request specifies a
- queue file, a sender address, a domain or host name that
- is treated as the reason for non-delivery, and recipient
+ queue file, a sender address, the reason for non-delivery
+ (specified as the next-hop destination), and recipient
information. The reason may be prefixed with an RFC
3463-compatible detail code. This program expects to be
run from the <a href="master.8.html"><b>master</b>(8)</a> process manager.
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#notify_classes">notify_classes</a> (resource, software)</b>
- The list of error classes that are reported to the
+ The list of error classes that are reported to the
postmaster.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>SEE ALSO</b>
syslogd(8), system logging
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
- <b><a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> (see 'postconf -d' out-</b>
+ <b><a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> (see 'postconf -d' out-</b>
<b>put)</b>
What Postfix features match subdomains of
"domain.tld" automatically, instead of requiring an
explicit ".domain.tld" pattern.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>FILES</b>
<a href="ETRN_README.html">ETRN_README</a>, Postfix ETRN howto
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>HISTORY</b>
that serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command. The
result, an indexed file in <b>dbm</b> or <b>db</b> format, is used for
fast searching by the mail system. Execute the command
- "<b>postmap /etc/postfix/generic</b>" in order to rebuild the
- indexed file after changing the text file.
+ "<b>postmap /etc/postfix/generic</b>" to rebuild an indexed file
+ after changing the corresponding text file.
When the table is provided via other means such as NIS,
LDAP or SQL, the same lookups are done as for ordinary
Alternatively, the table can be provided as a regular-
expression map where patterns are given as regular expres-
sions, or lookups can be directed to TCP-based server. In
- that case, the lookups are done in a slightly different
+ those case, the lookups are done in a slightly different
way as described below under "REGULAR EXPRESSION TABLES"
- and "TCP-BASED TABLES".
+ or "TCP-BASED TABLES".
<b>CASE FOLDING</b>
The search string is folded to lowercase before database
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#prepend_delivered_header">prepend_delivered_header</a> (command, file, forward)</b>
- The message delivery contexts where the Postfix
- <a href="local.8.html"><b>local</b>(8)</a> delivery agent prepends a Delivered-To:
- message header with the address that the mail was
+ The message delivery contexts where the Postfix
+ <a href="local.8.html"><b>local</b>(8)</a> delivery agent prepends a Delivered-To:
+ message header with the address that the mail was
delivered to.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#propagate_unmatched_extensions">propagate_unmatched_extensions</a> (canonical, virtual)</b>
- What address lookup tables copy an address exten-
+ What address lookup tables copy an address exten-
sion from the lookup key to the lookup result.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> (empty)</b>
sions (user+foo).
<b><a href="postconf.5.html#require_home_directory">require_home_directory</a> (no)</b>
- Whether or not a <a href="local.8.html"><b>local</b>(8)</a> recipient's home direc-
- tory must exist before mail delivery is attempted.
+ Whether or not a <a href="local.8.html"><b>local</b>(8)</a> recipient's home direc-
+ tory must exist before mail delivery is attempted.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>FILES</b>
syslogd(8), system logging
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>HISTORY</b>
The <b>Delivered-To:</b> message header appears in the <b>qmail</b> sys-
tem by Daniel Bernstein.
- The <i>maildir</i> structure appears in the <b>qmail</b> system by
+ The <i>maildir</i> structure appears in the <b>qmail</b> system by
Daniel Bernstein.
<b>AUTHOR(S)</b>
number server.
The behavior of the <a href="master.8.html"><b>master</b>(8)</a> daemon is controlled by the
- <
b>master.cf</b> configuration file, as described in <a href="master.5.html"><b>master</b>(5)</a>.
+ <
a href="master.5.html"><b>master.cf</b></a> configuration file, as described in <a href="master.5.html"><b>master</b>(5)</a>.
Options:
<b>-c</b> <i>config</i><b>_</b><i>dir</i>
- Read the <b>main.cf</b> and <b>master.cf</b> configuration files
+ Read the <a href="postconf.5.html"><b>main.cf</b></a> and <a href="master.5.html"><b>master.cf</b></a> configuration files
in the named directory instead of the default con-
figuration directory. This also overrides the con-
figuration files for other Postfix daemon pro-
<b>-D</b> After initialization, run a debugger on the master
process. The debugging command is specified with
- the <b><a href="postconf.5.html#debugger_command">debugger_command</a></b> in the <b>main.cf</b> global configu-
+ the <b><a href="postconf.5.html#debugger_command">debugger_command</a></b> in the <a href="postconf.5.html"><b>main.cf</b></a> global configu-
ration file.
<b>-d</b> Do not redirect stdin, stdout or stderr to
<b>SIGHUP</b> Upon receipt of a <b>HUP</b> signal (e.g., after "<b>postfix</b>
<b>reload</b>"), the master process re-reads its configu-
ration files. If a service has been removed from
- the <b>master.cf</b> file, its running processes are ter-
+ the <a href="master.5.html"><b>master.cf</b></a> file, its running processes are ter-
minated immediately. Otherwise, running processes
are allowed to terminate as soon as is convenient,
so that changes in configuration settings affect
<b>MAIL_DEBUG</b>
After initialization, start a debugger as specified
with the <b><a href="postconf.5.html#debugger_command">debugger_command</a></b> configuration parameter
- in the <b>main.cf</b> configuration file.
+ in the <a href="postconf.5.html"><b>main.cf</b></a> configuration file.
<b>MAIL_CONFIG</b>
Directory with Postfix configuration files.
<b>CONFIGURATION PARAMETERS</b>
Unlike most Postfix daemon processes, the <a href="master.8.html"><b>master</b>(8)</a> server
- does not automatically pick up changes to <b>main.cf</b>. Changes
- to <b>master.cf</b> are never picked up automatically. Use the
+ does not automatically pick up changes to <a href="postconf.5.html"><b>main.cf</b></a>. Changes
+ to <a href="master.5.html"><b>master.cf</b></a> are never picked up automatically. Use the
"<b>postfix reload</b>" command after a configuration change.
<b>RESOURCE AND RATE CONTROLS</b>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#service_throttle_time">service_throttle_time</a> (60s)</b>
How long the Postfix <a href="master.8.html"><b>master</b>(8)</a> waits before forking
<b>MISCELLANEOUS CONTROLS</b>
<b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
- The default location of the Postfix main.cf and
- master.cf configuration files.
+ The default location of the Postfix <a href="postconf.5.html">main.cf</a> and
+ <a href="master.5.html">master.cf</a> configuration files.
<b><a href="postconf.5.html#daemon_directory">daemon_directory</a> (see 'postconf -d' output)</b>
- The directory with Postfix support programs and
+ The directory with Postfix support programs and
daemon programs.
<b><a href="postconf.5.html#debugger_command">debugger_command</a> (empty)</b>
tem receives mail on.
<b><a href="postconf.5.html#inet_protocols">inet_protocols</a> (ipv4)</b>
- The Internet protocols Postfix will attempt to use
+ The Internet protocols Postfix will attempt to use
when making or accepting connections.
<b><a href="postconf.5.html#import_environment">import_environment</a> (see 'postconf -d' output)</b>
- The list of environment parameters that a Postfix
+ The list of environment parameters that a Postfix
process will import from a non-Postfix parent
process.
and most Postfix daemon processes.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>FILES</b>
- /etc/postfix/main.cf, global configuration file.
- /etc/postfix/master.cf, master server configuration file.
+ /etc/postfix/<a href="postconf.5.html">main.cf</a>, global configuration file.
+ /etc/postfix/<a href="master.5.html">master.cf</a>, master server configuration file.
/var/spool/postfix/pid/master.pid, master lock file.
<b>SEE ALSO</b>
<a href="qmgr.8.html">qmgr(8)</a>, queue manager
<a href="verify.8.html">verify(8)</a>, address verification
- <a href="master.5.html">master(5)</a>, master.cf configuration file syntax
- <a href="postconf.5.html">postconf(5)</a>, main.cf configuration parameter syntax
+ <a href="master.5.html">master(5)</a>, <a href="master.5.html">master.cf</a> configuration file syntax
+ <a href="postconf.5.html">postconf(5)</a>, <a href="postconf.5.html">main.cf</a> configuration parameter syntax
syslogd(8), system logging
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
Alternatively, lookup tables can be specified in Perl Com-
patible Regular Expression form. In this case, each input
- is compared against a list of patterns, and when a match
- is found the corresponding result is returned.
+ is compared against a list of patterns. When a match is
+ found, the corresponding result is returned and the search
+ is terminated.
- To find out what types of lookup tables your Postfix sys-
+ To find out what types of lookup tables your Postfix sys-
tem supports use the "<b>postconf -m</b>" command.
- To test lookup tables, use the "<b>postmap -fq</b>" command as
+ To test lookup tables, use the "<b>postmap -fq</b>" command as
described in the SYNOPSIS above.
<b>TABLE FORMAT</b>
responding <i>result</i> value.
<b>!/</b><i>pattern</i><b>/</b><i>flags result</i>
- When <i>pattern</i> does <b>not</b> match the input string, use
+ When <i>pattern</i> does <b>not</b> match the input string, use
the corresponding <i>result</i> value.
<b>if /</b><i>pattern</i><b>/</b><i>flags</i>
<b>endif</b> Match the input string against the patterns between
- <b>if</b> and <b>endif</b>, if and only if the input string also
+ <b>if</b> and <b>endif</b>, if and only if the input string also
matches <i>pattern</i>. The <b>if</b>..<b>endif</b> can nest.
- Note: do not prepend whitespace to patterns inside
+ Note: do not prepend whitespace to patterns inside
<b>if</b>..<b>endif</b>.
This feature is available in Postfix 2.1 and later.
<b>if !/</b><i>pattern</i><b>/</b><i>flags</i>
<b>endif</b> Match the input string against the patterns between
- <b>if</b> and <b>endif</b>, if and only if the input string does
+ <b>if</b> and <b>endif</b>, if and only if the input string does
<b>not</b> match <i>pattern</i>. The <b>if</b>..<b>endif</b> can nest.
- Note: do not prepend whitespace to patterns inside
+ Note: do not prepend whitespace to patterns inside
<b>if</b>..<b>endif</b>.
This feature is available in Postfix 2.1 and later.
blank lines and comments
- Empty lines and whitespace-only lines are ignored,
- as are lines whose first non-whitespace character
+ Empty lines and whitespace-only lines are ignored,
+ as are lines whose first non-whitespace character
is a `#'.
multi-line text
- A logical line starts with non-whitespace text. A
- line that starts with whitespace continues a logi-
+ A logical line starts with non-whitespace text. A
+ line that starts with whitespace continues a logi-
cal line.
Each pattern is a perl-like regular expression. The
- expression delimiter can be any character, except white-
- space or characters that have special meaning (tradition-
- ally the forward slash is used). The regular expression
+ expression delimiter can be any character, except white-
+ space or characters that have special meaning (tradition-
+ ally the forward slash is used). The regular expression
can contain whitespace.
By default, matching is case-insensitive, and newlines are
- not treated as special characters. The behavior is con-
- trolled by flags, which are toggled by appending one or
+ not treated as special characters. The behavior is con-
+ trolled by flags, which are toggled by appending one or
more of the following characters after the pattern:
<b>i</b> (default: on)
- Toggles the case sensitivity flag. By default,
+ Toggles the case sensitivity flag. By default,
matching is case insensitive.
<b>m</b> (default: off)
- Toggles the PCRE_MULTILINE flag. When this flag is
- on, the <b>^</b> and <b>$</b> metacharacters match immediately
- after and immediately before a newline character,
- respectively, in addition to matching at the start
+ Toggles the PCRE_MULTILINE flag. When this flag is
+ on, the <b>^</b> and <b>$</b> metacharacters match immediately
+ after and immediately before a newline character,
+ respectively, in addition to matching at the start
and end of the subject string.
<b>s</b> (default: on)
Toggles the PCRE_DOTALL flag. When this flag is on,
the <b>.</b> metacharacter matches the newline character.
With Postfix versions prior to 2.0, The flag is off
- by default, which is inconvenient for multi-line
+ by default, which is inconvenient for multi-line
message header matching.
<b>x</b> (default: off)
- Toggles the pcre extended flag. When this flag is
- on, whitespace in the pattern (other than in a
+ Toggles the pcre extended flag. When this flag is
+ on, whitespace in the pattern (other than in a
character class) and characters between a <b>#</b> outside
- a character class and the next newline character
- are ignored. An escaping backslash can be used to
- include a whitespace or <b>#</b> character as part of the
+ a character class and the next newline character
+ are ignored. An escaping backslash can be used to
+ include a whitespace or <b>#</b> character as part of the
pattern.
<b>A</b> (default: off)
- Toggles the PCRE_ANCHORED flag. When this flag is
- on, the pattern is forced to be "anchored", that
+ Toggles the PCRE_ANCHORED flag. When this flag is
+ on, the pattern is forced to be "anchored", that
is, it is constrained to match only at the start of
- the string which is being searched (the "subject
- string"). This effect can also be achieved by
+ the string which is being searched (the "subject
+ string"). This effect can also be achieved by
appropriate constructs in the pattern itself.
<b>E</b> (default: off)
- Toggles the PCRE_DOLLAR_ENDONLY flag. When this
- flag is on, a <b>$</b> metacharacter in the pattern
- matches only at the end of the subject string.
- Without this flag, a dollar also matches immedi-
+ Toggles the PCRE_DOLLAR_ENDONLY flag. When this
+ flag is on, a <b>$</b> metacharacter in the pattern
+ matches only at the end of the subject string.
+ Without this flag, a dollar also matches immedi-
ately before the final character if it is a newline
character (but not before any other newline charac-
- ters). This flag is ignored if PCRE_MULTILINE flag
+ ters). This flag is ignored if PCRE_MULTILINE flag
is set.
<b>U</b> (default: off)
Toggles the ungreedy matching flag. When this flag
- is on, the pattern matching engine inverts the
- "greediness" of the quantifiers so that they are
- not greedy by default, but become greedy if fol-
- lowed by "?". This flag can also set by a (?U)
+ is on, the pattern matching engine inverts the
+ "greediness" of the quantifiers so that they are
+ not greedy by default, but become greedy if fol-
+ lowed by "?". This flag can also set by a (?U)
modifier within the pattern.
<b>X</b> (default: off)
Toggles the PCRE_EXTRA flag. When this flag is on,
- any backslash in a pattern that is followed by a
+ any backslash in a pattern that is followed by a
letter that has no special meaning causes an error,
thus reserving these combinations for future expan-
sion.
<b>SEARCH ORDER</b>
- Patterns are applied in the order as specified in the ta-
- ble, until a pattern is found that matches the input
+ Patterns are applied in the order as specified in the ta-
+ ble, until a pattern is found that matches the input
string.
- Each pattern is applied to the entire input string.
- Depending on the application, that string is an entire
+ Each pattern is applied to the entire input string.
+ Depending on the application, that string is an entire
client hostname, an entire client IP address, or an entire
- mail address. Thus, no parent domain or parent network
- search is done, and <i>user@domain</i> mail addresses are not
- broken up into their <i>user</i> and <i>domain</i> constituent parts,
+ mail address. Thus, no parent domain or parent network
+ search is done, and <i>user@domain</i> mail addresses are not
+ broken up into their <i>user</i> and <i>domain</i> constituent parts,
nor is <i>user+foo</i> broken up into <i>user</i> and <i>foo</i>.
<b>TEXT SUBSTITUTION</b>
- Substitution of substrings from the matched expression
- into the result string is possible using the conventional
- perl syntax ($1, $2, etc.); specify $$ to produce a $
- character as output. The macros in the result string may
+ Substitution of substrings from the matched expression
+ into the result string is possible using the conventional
+ perl syntax ($1, $2, etc.); specify $$ to produce a $
+ character as output. The macros in the result string may
need to be written as ${n} or $(n) if they aren't followed
by whitespace.
- Note: since negated patterns (those preceded by <b>!</b>) return
+ Note: since negated patterns (those preceded by <b>!</b>) return
a result when the expression does not match, substitutions
are not available for negated patterns.
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>SEE ALSO</b>
syslogd(8), system logging
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> (empty)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>SEE ALSO</b>
syslogd(8), system logging
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
<ul>
-<li> a = time before the queue manager, including message transmission
+<li> a = time from message arrival to last <a href="QSHAPE_README.html#active_queue">active queue</a> entry
-<li> b = time in queue manager
+<li> b = time from last <a href="QSHAPE_README.html#active_queue">active queue</a> entry to connection setup
<li> c = time in connection setup, including DNS, EHLO and TLS
</DD>
<DT><b><a name="lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a>
-(default: $<a href="postconf.5.html#myhostname">myhostname</a>)</b></DT><DD>
+(default: empty)</b></DT><DD>
<p> A case insensitive list of LHLO keywords (pipelining, starttls,
auth, etc.) that the LMTP client will ignore in the LHLO response
(default: 100s)</b></DT><DD>
<p>
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting. This parameter
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily. This
+parameter
is ignored by the Postfix queue manager and by other long-lived
Postfix daemon processes.
</p>
(default: 100)</b></DT><DD>
<p>
-The maximal number of connection requests before a Postfix daemon
-process terminates. This parameter is ignored by the Postfix queue
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily. This parameter
+is ignored by the Postfix queue
manager and by other long-lived Postfix daemon processes.
</p>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#proxy_read_maps">proxy_read_maps</a> (see 'postconf -d' output)</b>
- The lookup tables that the <a href="proxymap.8.html"><b>proxymap</b>(8)</a> server is
+ The lookup tables that the <a href="proxymap.8.html"><b>proxymap</b>(8)</a> server is
allowed to access.
<b>SEE ALSO</b>
<a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>HISTORY</b>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#qmqpd_authorized_clients">qmqpd_authorized_clients</a> (empty)</b>
- What clients are allowed to connect to the QMQP
+ What clients are allowed to connect to the QMQP
server port.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b><a href="postconf.5.html#verp_delimiter_filter">verp_delimiter_filter</a> (-=+)</b>
- The characters Postfix accepts as VERP delimiter
- characters on the Postfix <a href="sendmail.1.html"><b>sendmail</b>(1)</a> command line
+ The characters Postfix accepts as VERP delimiter
+ characters on the Postfix <a href="sendmail.1.html"><b>sendmail</b>(1)</a> command line
and in SMTP commands.
<b>SEE ALSO</b>
<a href="QMQP_README.html">QMQP_README</a>, Postfix ezmlm-idx howto.
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>HISTORY</b>
<b>qshape</b> [<b>-s</b>] [<b>-p</b>] [<b>-m</b> <i>min</i><b>_</b><i>subdomains</i>]
[<b>-b</b> <i>bucket</i><b>_</b><i>count</i>] [<b>-t</b> <i>bucket</i><b>_</b><i>time</i>]
[<b>-l</b>] [<b>-w</b> <i>terminal</i><b>_</b><i>width</i>]
+ [<b>-N</b> <i>batch</i><b>_</b><i>msg</i><b>_</b><i>count</i>] [<b>-n</b> <i>batch</i><b>_</b><i>top</i><b>_</b><i>domains</i>]
[<b>-c</b> <i>config</i><b>_</b><i>directory</i>] [<i>queue</i><b>_</b><i>name</i> ...]
<b>DESCRIPTION</b>
narrow to show the domain name and all the coun-
ters, the terminal_width limit is violated.
+ <b>-N</b> <i>batch</i><b>_</b><i>msg</i><b>_</b><i>count</i>
+ When the output device is a terminal, intermediate
+ results are shown each "batch_msg_count" messages.
+ This produces usable results in a reasonable time
+ even when the <a href="QSHAPE_README.html#deferred_queue">deferred queue</a> is large. The default
+ is to show intermediate results every 1000 mes-
+ sages.
+
+ <b>-n</b> <i>batch</i><b>_</b><i>top</i><b>_</b><i>domains</i>
+ When reporting intermediate or final results to a
+ termainal, report only the top "batch_top_domains"
+ domains. The default limit is 20 domains.
+
<b>-c</b> <i>config</i><b>_</b><i>directory</i>
- The <a href="postconf.5.html"><b>main.cf</b></a> configuration file is in the named
+ The <a href="postconf.5.html"><b>main.cf</b></a> configuration file is in the named
directory instead of the default configuration
directory.
Arguments:
<i>queue</i><b>_</b><i>name</i>
- By default <b>qshape</b> displays the combined distribu-
- tion of the <a href="QSHAPE_README.html#incoming_queue">incoming</a> and <a href="QSHAPE_README.html#active_queue">active queues</a>. To display
- a different set of queues, just list their direc-
+ By default <b>qshape</b> displays the combined distribu-
+ tion of the <a href="QSHAPE_README.html#incoming_queue">incoming</a> and <a href="QSHAPE_README.html#active_queue">active queues</a>. To display
+ a different set of queues, just list their direc-
tory names on the command line. Absolute paths are
- used as is, other paths are taken relative to the
- <a href="postconf.5.html"><b>main.cf</a> <a href="postconf.5.html#queue_directory">queue_directory</a></b> parameter setting. While
- <a href="postconf.5.html"><b>main.cf</b></a> supports the use of <i>$variable</i> expansion in
- the definition of the <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> parameter,
- the <b>qshape</b> program does not. If you must use vari-
+ used as is, other paths are taken relative to the
+ <a href="postconf.5.html"><b>main.cf</a> <a href="postconf.5.html#queue_directory">queue_directory</a></b> parameter setting. While
+ <a href="postconf.5.html"><b>main.cf</b></a> supports the use of <i>$variable</i> expansion in
+ the definition of the <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> parameter,
+ the <b>qshape</b> program does not. If you must use vari-
able expansions in the <b><a href="postconf.5.html#queue_directory">queue_directory</a></b> setting, you
- must specify an explicit absolute path for each
- queue subdirectory even if you want the default
+ must specify an explicit absolute path for each
+ queue subdirectory even if you want the default
<a href="QSHAPE_README.html#incoming_queue">incoming</a> and <a href="QSHAPE_README.html#active_queue">active queue</a> distribution.
<b>SEE ALSO</b>
$<a href="postconf.5.html#queue_directory">queue_directory</a>/deferred/, messages postponed for later delivery.
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
Alternatively, lookup tables can be specified in POSIX
regular expression form. In this case, each input is com-
- pared against a list of patterns, and when a match is
- found the corresponding result is returned.
+ pared against a list of patterns. When a match is found,
+ the corresponding result is returned and the search is
+ terminated.
- To find out what types of lookup tables your Postfix sys-
+ To find out what types of lookup tables your Postfix sys-
tem supports use the "<b>postconf -m</b>" command.
- To test lookup tables, use the "<b>postmap -fq</b>" command as
+ To test lookup tables, use the "<b>postmap -fq</b>" command as
described in the SYNOPSIS above.
<b>TABLE FORMAT</b>
responding <i>result</i> value.
<b>!/</b><i>pattern</i><b>/</b><i>flags result</i>
- When <i>pattern</i> does <b>not</b> match the input string, use
+ When <i>pattern</i> does <b>not</b> match the input string, use
the corresponding <i>result</i> value.
<b>if /</b><i>pattern</i><b>/</b><i>flags</i>
<b>if</b> and <b>endif</b>, if and only if that same input string
also matches <i>pattern</i>. The <b>if</b>..<b>endif</b> can nest.
- Note: do not prepend whitespace to patterns inside
+ Note: do not prepend whitespace to patterns inside
<b>if</b>..<b>endif</b>.
This feature is available in Postfix 2.1 and later.
<b>endif</b> Match the input string against the patterns between
<b>if</b> and <b>endif</b>, if and only if that same input string
- does <b>not</b> match <i>pattern</i>. The <b>if</b>..<b>endif</b> can nest.
+ does <b>not</b> match <i>pattern</i>. The <b>if</b>..<b>endif</b> can nest.
matches <i>pattern</i>. The <b>if</b>..<b>endif</b> can nest.
- Note: do not prepend whitespace to patterns inside
+ Note: do not prepend whitespace to patterns inside
<b>if</b>..<b>endif</b>.
This feature is available in Postfix 2.1 and later.
blank lines and comments
- Empty lines and whitespace-only lines are ignored,
- as are lines whose first non-whitespace character
+ Empty lines and whitespace-only lines are ignored,
+ as are lines whose first non-whitespace character
is a `#'.
multi-line text
- A logical line starts with non-whitespace text. A
- line that starts with whitespace continues a logi-
+ A logical line starts with non-whitespace text. A
+ line that starts with whitespace continues a logi-
cal line.
- Each pattern is a POSIX regular expression enclosed by a
+ Each pattern is a POSIX regular expression enclosed by a
pair of delimiters. The regular expression syntax is docu-
- mented in <b>re_format</b>(7) with 4.4BSD, in <b>regex</b>(5) with
+ mented in <b>re_format</b>(7) with 4.4BSD, in <b>regex</b>(5) with
Solaris, and in <b>regex</b>(7) with Linux. Other systems may use
other document names.
- The expression delimiter can be any character, except
+ The expression delimiter can be any character, except
whitespace or characters that have special meaning (tradi-
- tionally the forward slash is used). The regular expres-
+ tionally the forward slash is used). The regular expres-
sion can contain whitespace.
By default, matching is case-insensitive, and newlines are
- not treated as special characters. The behavior is con-
- trolled by flags, which are toggled by appending one or
+ not treated as special characters. The behavior is con-
+ trolled by flags, which are toggled by appending one or
more of the following characters after the pattern:
<b>i</b> (default: on)
- Toggles the case sensitivity flag. By default,
+ Toggles the case sensitivity flag. By default,
matching is case insensitive.
<b>x</b> (default: on)
- Toggles the extended expression syntax flag. By
- default, support for extended expression syntax is
+ Toggles the extended expression syntax flag. By
+ default, support for extended expression syntax is
enabled.
<b>m</b> (default: off)
- Toggle the multi-line mode flag. When this flag is
- on, the <b>^</b> and <b>$</b> metacharacters match immediately
- after and immediately before a newline character,
- respectively, in addition to matching at the start
+ Toggle the multi-line mode flag. When this flag is
+ on, the <b>^</b> and <b>$</b> metacharacters match immediately
+ after and immediately before a newline character,
+ respectively, in addition to matching at the start
and end of the input string.
<b>TABLE SEARCH ORDER</b>
- Patterns are applied in the order as specified in the ta-
- ble, until a pattern is found that matches the input
+ Patterns are applied in the order as specified in the ta-
+ ble, until a pattern is found that matches the input
string.
- Each pattern is applied to the entire input string.
- Depending on the application, that string is an entire
+ Each pattern is applied to the entire input string.
+ Depending on the application, that string is an entire
client hostname, an entire client IP address, or an entire
- mail address. Thus, no parent domain or parent network
- search is done, and <i>user@domain</i> mail addresses are not
- broken up into their <i>user</i> and <i>domain</i> constituent parts,
+ mail address. Thus, no parent domain or parent network
+ search is done, and <i>user@domain</i> mail addresses are not
+ broken up into their <i>user</i> and <i>domain</i> constituent parts,
nor is <i>user+foo</i> broken up into <i>user</i> and <i>foo</i>.
<b>TEXT SUBSTITUTION</b>
- Substitution of substrings from the matched expression
- into the result string is possible using $1, $2, etc.;
+ Substitution of substrings from the matched expression
+ into the result string is possible using $1, $2, etc.;
specify $$ to produce a $ character as output. The macros
- in the result string may need to be written as ${n} or
+ in the result string may need to be written as ${n} or
$(n) if they aren't followed by whitespace.
- Note: since negated patterns (those preceded by <b>!</b>) return
+ Note: since negated patterns (those preceded by <b>!</b>) return
a result when the expression does not match, substitutions
are not available for negated patterns.
file that serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command. The
result, an indexed file in <b>dbm</b> or <b>db</b> format, is used for
fast searching by the mail system. Execute the command
- "<b>postmap /etc/postfix/relocated</b>" in order to rebuild the
- indexed file after changing the relocated table.
+ "<b>postmap /etc/postfix/relocated</b>" to rebuild an indexed
+ file after changing the corresponding relocated table.
When the table is provided via other means such as NIS,
LDAP or SQL, the same lookups are done as for ordinary
Alternatively, the table can be provided as a regular-
expression map where patterns are given as regular expres-
sions, or lookups can be directed to TCP-based server. In
- that case, the lookups are done in a slightly different
+ those case, the lookups are done in a slightly different
way as described below under "REGULAR EXPRESSION TABLES"
- and "TCP-BASED TABLES".
+ or "TCP-BASED TABLES".
Table lookups are case insensitive.
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
The process ID of a Postfix command or daemon
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>FILES</b>
syslogd(8), system logging
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
By default, connection caching is enabled temporarily for
destinations that have a high volume of mail in the active
- queue. Session caching can be enabled permanently for spe-
- cific destinations.
+ queue. Connection caching can be enabled permanently for
+ specific destinations.
<b>SMTP DESTINATION SYNTAX</b>
SMTP destinations have the following form:
LMTP client will ignore in the LHLO response from a
remote LMTP server.
- <b><a href="postconf.5.html#lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
+ <b><a href="postconf.5.html#lmtp_discard_lhlo_keywords">lmtp_discard_lhlo_keywords</a> (empty)</b>
A case insensitive list of LHLO keywords (pipelin-
ing, starttls, auth, etc.) that the LMTP client
will ignore in the LHLO response from a remote LMTP
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> (empty)</b>
The network interface addresses that this mail sys-
- tem receives mail on by way of a proxy or network
+ tem receives mail on by way of a proxy or network
address translation unit.
<b><a href="postconf.5.html#smtp_bind_address">smtp_bind_address</a> (empty)</b>
- An optional numerical network address that the
- Postfix SMTP client should bind to when making an
+ An optional numerical network address that the
+ Postfix SMTP client should bind to when making an
IPv4 connection.
<b><a href="postconf.5.html#smtp_bind_address6">smtp_bind_address6</a> (empty)</b>
- An optional numerical network address that the
- Postfix SMTP client should bind to when making an
+ An optional numerical network address that the
+ Postfix SMTP client should bind to when making an
IPv6 connection.
<b><a href="postconf.5.html#smtp_helo_name">smtp_helo_name</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
- The hostname to send in the SMTP EHLO or HELO com-
+ The hostname to send in the SMTP EHLO or HELO com-
mand.
<b><a href="postconf.5.html#lmtp_lhloname">lmtp_lhlo_name</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
The hostname to send in the LMTP LHLO command.
<b><a href="postconf.5.html#smtp_host_lookup">smtp_host_lookup</a> (dns)</b>
- What mechanisms when the Postfix SMTP client uses
+ What mechanisms when the Postfix SMTP client uses
to look up a host's IP address.
<b><a href="postconf.5.html#smtp_randomize_addresses">smtp_randomize_addresses</a> (yes)</b>
- Randomize the order of equal-preference MX host
+ Randomize the order of equal-preference MX host
addresses.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
Available with Postfix 2.2 and earlier:
<b><a href="postconf.5.html#fallback_relay">fallback_relay</a> (empty)</b>
- Optional list of relay hosts for SMTP destinations
+ Optional list of relay hosts for SMTP destinations
that can't be found or that are unreachable.
Available with Postfix 2.3 and later:
<b><a href="postconf.5.html#smtp_fallback_relay">smtp_fallback_relay</a> ($<a href="postconf.5.html#fallback_relay">fallback_relay</a>)</b>
- Optional list of relay hosts for SMTP destinations
+ Optional list of relay hosts for SMTP destinations
that can't be found or that are unreachable.
<b>SEE ALSO</b>
<a href="TLS_README.html">TLS_README</a>, Postfix STARTTLS howto
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#myhostname">myhostname</a> (see 'postconf -d' output)</b>
The internet hostname of this mail system.
<b><a href="postconf.5.html#mynetworks">mynetworks</a> (see 'postconf -d' output)</b>
- The list of "trusted" SMTP clients that have more
+ The list of "trusted" SMTP clients that have more
privileges than "strangers".
<b><a href="postconf.5.html#myorigin">myorigin</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
The domain name that locally-posted mail appears to
- come from, and that locally posted mail is deliv-
+ come from, and that locally posted mail is deliv-
ered to.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> (empty)</b>
sions (user+foo).
<b><a href="postconf.5.html#smtpd_banner">smtpd_banner</a> ($<a href="postconf.5.html#myhostname">myhostname</a> ESMTP $<a href="postconf.5.html#mail_name">mail_name</a>)</b>
- The text that follows the 220 status code in the
+ The text that follows the 220 status code in the
SMTP greeting banner.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
Available in Postfix version 2.2 and later:
<b><a href="postconf.5.html#smtpd_forbidden_commands">smtpd_forbidden_commands</a> (CONNECT, GET, POST)</b>
- List of commands that causes the Postfix SMTP
- server to immediately terminate the session with a
+ List of commands that causes the Postfix SMTP
+ server to immediately terminate the session with a
221 code.
<b>SEE ALSO</b>
<a href="XFORWARD_README.html">XFORWARD_README</a>, Postfix XFORWARD extension
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>SEE ALSO</b>
syslogd(8), system logging
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
file that serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command. The
result, an indexed file in <b>dbm</b> or <b>db</b> format, is used for
fast searching by the mail system. Execute the command
- "<b>postmap /etc/postfix/transport</b>" in order to rebuild the
- indexed file after changing the transport table.
+ "<b>postmap /etc/postfix/transport</b>" to rebuild an indexed
+ file after changing the corresponding transport table.
When the table is provided via other means such as NIS,
LDAP or SQL, the same lookups are done as for ordinary
Alternatively, the table can be provided as a regular-
expression map where patterns are given as regular expres-
sions, or lookups can be directed to TCP-based server. In
- that case, the lookups are done in a slightly different
+ those case, the lookups are done in a slightly different
way as described below under "REGULAR EXPRESSION TABLES"
- and "TCP-BASED TABLES".
+ or "TCP-BASED TABLES".
<b>CASE FOLDING</b>
The search string is folded to lowercase before database
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#relocated_maps">relocated_maps</a> (empty)</b>
Optional lookup tables with new contact information
for users or domains that no longer exist.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#show_user_unknown_table_name">show_user_unknown_table_name</a> (yes)</b>
- Display the name of the recipient table in the
+ Display the name of the recipient table in the
"User unknown" responses.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
Available in Postfix version 2.0 and later:
<b><a href="postconf.5.html#helpful_warnings">helpful_warnings</a> (yes)</b>
- Log warnings about problematic configuration set-
+ Log warnings about problematic configuration set-
tings, and provide helpful suggestions.
<b>SEE ALSO</b>
<a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VERIFICATION_README</a>, Postfix address verification
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
text file that serves as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command.
The result, an indexed file in <b>dbm</b> or <b>db</b> format, is used
for fast searching by the mail system. Execute the command
- "<b>postmap /etc/postfix/virtual</b>" in order to rebuild the
- indexed file after changing the text file.
+ "<b>postmap /etc/postfix/virtual</b>" to rebuild an indexed file
+ after changing the corresponding text file.
When the table is provided via other means such as NIS,
LDAP or SQL, the same lookups are done as for ordinary
Alternatively, the table can be provided as a regular-
expression map where patterns are given as regular expres-
sions, or lookups can be directed to TCP-based server. In
- that case, the lookups are done in a slightly different
+ those case, the lookups are done in a slightly different
way as described below under "REGULAR EXPRESSION TABLES"
- and "TCP-BASED TABLES".
+ or "TCP-BASED TABLES".
<b>CASE FOLDING</b>
The search string is folded to lowercase before database
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
- daemon process waits for the next service request
- before exiting.
+ daemon process waits for an incoming connection
+ before terminating voluntarily.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
- The maximal number of connection requests before a
- Postfix daemon process terminates.
+ The maximal number of incoming connections that a
+ Postfix daemon process will service before termi-
+ nating voluntarily.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
- The process ID of a Postfix command or daemon
+ The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
- The process name of a Postfix command or daemon
+ The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
- The location of the Postfix top-level queue direc-
+ The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
- The mail system name that is prepended to the
- process name in syslog records, so that "smtpd"
+ The mail system name that is prepended to the
+ process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>SEE ALSO</b>
<a href="VIRTUAL_README.html">VIRTUAL_README</a>, domain hosting howto
<b>LICENSE</b>
- The Secure Mailer license must be distributed with this
+ The Secure Mailer license must be distributed with this
software.
<b>HISTORY</b>
- This delivery agent was originally based on the Postfix
- local delivery agent. Modifications mainly consisted of
- removing code that either was not applicable or that was
- not safe in this context: aliases, ~user/.forward files,
+ This delivery agent was originally based on the Postfix
+ local delivery agent. Modifications mainly consisted of
+ removing code that either was not applicable or that was
+ not safe in this context: aliases, ~user/.forward files,
delivery to "|command" or to /file/name.
The <b>Delivered-To:</b> message header appears in the <b>qmail</b> sys-
tem by Daniel Bernstein.
- The <b>maildir</b> structure appears in the <b>qmail</b> system by
+ The <b>maildir</b> structure appears in the <b>qmail</b> system by
Daniel Bernstein.
<b>AUTHOR(S)</b>
\fBqshape\fR [\fB-s\fR] [\fB-p\fR] [\fB-m \fImin_subdomains\fR]
[\fB-b \fIbucket_count\fR] [\fB-t \fIbucket_time\fR]
[\fB-l\fR] [\fB-w \fIterminal_width\fR]
+ [\fB-N \fIbatch_msg_count\fR] [\fB-n \fIbatch_top_domains\fR]
[\fB-c \fIconfig_directory\fR] [\fIqueue_name\fR ...]
.SH DESCRIPTION
.ad
parent domain rows are shown as '.+' followed by the last 16 bytes
of the domain name. If this is still too narrow to show the domain
name and all the counters, the terminal_width limit is violated.
+.IP "\fB-N \fIbatch_msg_count\fR"
+When the output device is a terminal, intermediate results are
+shown each "batch_msg_count" messages. This produces usable results
+in a reasonable time even when the deferred queue is large. The
+default is to show intermediate results every 1000 messages.
+.IP "\fB-n \fIbatch_top_domains\fR"
+When reporting intermediate or final results to a termainal, report
+only the top "batch_top_domains" domains. The default limit is 20
+domains.
.IP "\fB-c \fIconfig_directory\fR"
The \fBmain.cf\fR configuration file is in the named directory
instead of the default configuration directory.
.SH NAME
access
\-
-Postfix access table format
+Postfix SMTP server access table
.SH "SYNOPSIS"
.na
.nf
.SH DESCRIPTION
.ad
.fi
-The optional \fBaccess\fR(5) table directs the Postfix SMTP server
-to selectively reject or accept mail. Access can be allowed or
-denied for specific host names, domain names, networks, host
-addresses or mail addresses.
-
-For an example, see the EXAMPLE section at the end of this
-manual page.
+The Postfix SMTP server \fBaccess\fR(5) table specifies
+actions that are triggered by information from or about
+remote SMTP clients: host names, network addresses, or email
+addresses. An action may grant or deny access, or it may
+change the way that an email transaction will be handled.
Normally, the \fBaccess\fR(5) table is specified as a text file
that serves as input to the \fBpostmap\fR(1) command.
The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
-is used for fast searching by the mail system. Execute the command
-"\fBpostmap /etc/postfix/access\fR" in order to rebuild the indexed
-file after changing the access table.
+is used for fast searching by the mail system. Execute the
+command "\fBpostmap /etc/postfix/access\fR" to rebuild an
+indexed file after changing the corresponding text file.
When the table is provided via other means such as NIS, LDAP
or SQL, the same lookups are done as for ordinary indexed files.
Alternatively, the table can be provided as a regular-expression
map where patterns are given as regular expressions, or lookups
-can be directed to TCP-based server. In that case, the lookups are
-done in a slightly different way as described below under
-"REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+can be directed to TCP-based server. In those cases, the lookups
+are done in a slightly different way as described below under
+"REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
.SH "CASE FOLDING"
.na
.nf
This feature is available in Postfix 2.0 and later.
.IP "\fBPREPEND \fIheadername: headervalue\fR"
Prepend the specified message header to the message.
-When this action is used multiple times, the first prepended
+When this action executes multiple times, the first prepended
header appears before the second etc. prepended header.
.sp
Note: this action does not support multi-line message headers.
.sp
-Note: this action must be used before the message content
-is received; it cannot be used in \fBsmtpd_end_of_data_restrictions\fR.
+Note: this action must execute before the message content
+is received; it cannot execute in the context of
+\fBsmtpd_end_of_data_restrictions\fR.
.sp
This feature is available in Postfix 2.1 and later.
.IP "\fBREDIRECT \fIuser@domain\fR"
that serves as input to the \fBpostmap\fR(1) command.
The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
is used for fast searching by the mail system. Execute the command
-"\fBpostmap /etc/postfix/canonical\fR" in order to rebuild the indexed
-file after changing the text file.
+"\fBpostmap /etc/postfix/canonical\fR" to rebuild an indexed
+file after changing the corresponding text file.
When the table is provided via other means such as NIS, LDAP
or SQL, the same lookups are done as for ordinary indexed files.
Alternatively, the table can be provided as a regular-expression
map where patterns are given as regular expressions, or lookups
-can be directed to TCP-based server. In that case, the lookups are
-done in a slightly different way as described below under
-"REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+can be directed to TCP-based server. In those cases, the lookups
+are done in a slightly different way as described below under
+"REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
By default the \fBcanonical\fR(5) mapping affects both message
header addresses (i.e. addresses that appear inside messages)
The Postfix mail system uses optional lookup tables.
These tables are usually in \fBdbm\fR or \fBdb\fR format.
Alternatively, lookup tables can be specified in CIDR
-(Classless Inter-Domain Routing) form.
+(Classless Inter-Domain Routing) form. In this case, each
+input is compared against a list of patterns. When a match
+is found, the corresponding result is returned and the search
+is terminated.
To find out what types of lookup tables your Postfix system
supports use the "\fBpostconf -m\fR" command.
command. The result, an indexed file in \fBdbm\fR or
\fBdb\fR format, is used for fast searching by the mail
system. Execute the command "\fBpostmap /etc/postfix/generic\fR"
-in order to rebuild the indexed file after changing the
+to rebuild an indexed file after changing the corresponding
text file.
When the table is provided via other means such as NIS, LDAP
Alternatively, the table can be provided as a regular-expression
map where patterns are given as regular expressions, or lookups
-can be directed to TCP-based server. In that case, the lookups are
-done in a slightly different way as described below under
-"REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+can be directed to TCP-based server. In those case, the lookups
+are done in a slightly different way as described below under
+"REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
.SH "CASE FOLDING"
.na
.nf
Alternatively, lookup tables can be specified in Perl Compatible
Regular Expression form. In this case, each input is compared
-against a list of patterns, and when a match is found the
-corresponding result is returned.
+against a list of patterns. When a match is found, the
+corresponding result is returned and the search is terminated.
To find out what types of lookup tables your Postfix system
supports use the "\fBpostconf -m\fR" command.
.PP
The format of the "delays=a/b/c/d" logging is as follows:
.IP \(bu
-a = time before the queue manager, including message transmission
+a = time from message arrival to last active queue entry
.IP \(bu
-b = time in queue manager
+b = time from last active queue entry to connection setup
.IP \(bu
c = time in connection setup, including DNS, EHLO and TLS
.IP \(bu
smtpd_discard_ehlo_keyword_address_maps.
.PP
This feature is available in Postfix 2.3 and later.
-.SH lmtp_discard_lhlo_keywords (default: $myhostname)
+.SH lmtp_discard_lhlo_keywords (default: empty)
A case insensitive list of LHLO keywords (pipelining, starttls,
auth, etc.) that the LMTP client will ignore in the LHLO response
from a remote LMTP server.
.ad
.ft R
.SH max_idle (default: 100s)
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting. This parameter
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily. This
+parameter
is ignored by the Postfix queue manager and by other long-lived
Postfix daemon processes.
.PP
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks).
The default time unit is s (seconds).
.SH max_use (default: 100)
-The maximal number of connection requests before a Postfix daemon
-process terminates. This parameter is ignored by the Postfix queue
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily. This parameter
+is ignored by the Postfix queue
manager and by other long-lived Postfix daemon processes.
.SH maximal_backoff_time (default: 4000s)
The maximal time between attempts to deliver a deferred message.
Alternatively, lookup tables can be specified in POSIX regular
expression form. In this case, each input is compared against a
-list of patterns, and when a match is found the corresponding
-result is returned.
+list of patterns. When a match is found, the corresponding
+result is returned and the search is terminated.
To find out what types of lookup tables your Postfix system
supports use the "\fBpostconf -m\fR" command.
that serves as input to the \fBpostmap\fR(1) command.
The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
is used for fast searching by the mail system. Execute the command
-"\fBpostmap /etc/postfix/relocated\fR" in order to rebuild the indexed
-file after changing the relocated table.
+"\fBpostmap /etc/postfix/relocated\fR" to rebuild an indexed
+file after changing the corresponding relocated table.
When the table is provided via other means such as NIS, LDAP
or SQL, the same lookups are done as for ordinary indexed files.
Alternatively, the table can be provided as a regular-expression
map where patterns are given as regular expressions, or lookups
-can be directed to TCP-based server. In that case, the lookups are
-done in a slightly different way as described below under
-"REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+can be directed to TCP-based server. In those case, the lookups
+are done in a slightly different way as described below under
+"REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
Table lookups are case insensitive.
.SH "CASE FOLDING"
that serves as input to the \fBpostmap\fR(1) command.
The result, an indexed file in \fBdbm\fR or \fBdb\fR format, is used
for fast searching by the mail system. Execute the command
-"\fBpostmap /etc/postfix/transport\fR" in order to rebuild the indexed
-file after changing the transport table.
+"\fBpostmap /etc/postfix/transport\fR" to rebuild an indexed
+file after changing the corresponding transport table.
When the table is provided via other means such as NIS, LDAP
or SQL, the same lookups are done as for ordinary indexed files.
Alternatively, the table can be provided as a regular-expression
map where patterns are given as regular expressions, or lookups
-can be directed to TCP-based server. In that case, the lookups are
-done in a slightly different way as described below under
-"REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+can be directed to TCP-based server. In those case, the lookups
+are done in a slightly different way as described below under
+"REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
.SH "CASE FOLDING"
.na
.nf
that serves as input to the \fBpostmap\fR(1) command.
The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
is used for fast searching by the mail system. Execute the command
-"\fBpostmap /etc/postfix/virtual\fR" in order to rebuild the indexed
-file after changing the text file.
+"\fBpostmap /etc/postfix/virtual\fR" to rebuild an indexed
+file after changing the corresponding text file.
When the table is provided via other means such as NIS, LDAP
or SQL, the same lookups are done as for ordinary indexed files.
Alternatively, the table can be provided as a regular-expression
map where patterns are given as regular expressions, or lookups
-can be directed to TCP-based server. In that case, the lookups are
-done in a slightly different way as described below under
-"REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+can be directed to TCP-based server. In those case, the lookups
+are done in a slightly different way as described below under
+"REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
.SH "CASE FOLDING"
.na
.nf
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
The mail system name that is displayed in Received: headers, in
the SMTP greeting banner, and in bounced mail.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBnotify_classes (resource, software)\fR"
The list of error classes that are reported to the postmaster.
.IP "\fBprocess_id (read-only)\fR"
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBmyhostname (see 'postconf -d' output)\fR"
The internet hostname of this mail system.
.IP "\fBmyorigin ($myhostname)\fR"
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
The Postfix \fBerror\fR(8) delivery agent processes delivery
requests from
the queue manager. Each request specifies a queue file, a sender
-address, a domain or host name that is treated as the reason for
-non-delivery, and recipient information.
+address, the reason for non-delivery (specified as the
+next-hop destination), and recipient information.
The reason may be prefixed with an RFC 3463-compatible detail code.
This program expects to be run from the \fBmaster\fR(8) process
manager.
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBnotify_classes (resource, software)\fR"
The list of error classes that are reported to the postmaster.
.IP "\fBprocess_id (read-only)\fR"
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBparent_domain_matches_subdomains (see 'postconf -d' output)\fR"
What Postfix features match subdomains of "domain.tld" automatically,
instead of requiring an explicit ".domain.tld" pattern.
.IP "\fBlocal_command_shell (empty)\fR"
Optional shell program for \fBlocal\fR(8) delivery to non-Postfix command.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprepend_delivered_header (command, file, forward)\fR"
The message delivery contexts where the Postfix \fBlocal\fR(8) delivery
agent prepends a Delivered-To: message header with the address
The default maximal number of Postfix child processes that provide
a given service.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBservice_throttle_time (60s)\fR"
How long the Postfix \fBmaster\fR(8) waits before forking a server that
appears to be malfunctioning.
Upon input, long lines are chopped up into pieces of at most
this length; upon delivery, long lines are reconstructed.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
The UNIX system account that owns the Postfix queue and most Postfix
daemon processes.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
By default, connection caching is enabled temporarily for
destinations that have a high volume of mail in the active
-queue. Session caching can be enabled permanently for
+queue. Connection caching can be enabled permanently for
specific destinations.
.SH "SMTP DESTINATION SYNTAX"
.na
case insensitive lists of LHLO keywords (pipelining, starttls,
auth, etc.) that the LMTP client will ignore in the LHLO response
from a remote LMTP server.
-.IP "\fBlmtp_discard_lhlo_keywords ($myhostname)\fR"
+.IP "\fBlmtp_discard_lhlo_keywords (empty)\fR"
A case insensitive list of LHLO keywords (pipelining, starttls,
auth, etc.) that the LMTP client will ignore in the LHLO response
from a remote LMTP server.
.IP "\fBlmtp_tcp_port (24)\fR"
The default TCP port that the Postfix LMTP client connects to.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
The UNIX system account that owns the Postfix queue and most Postfix
daemon processes.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBmyhostname (see 'postconf -d' output)\fR"
The internet hostname of this mail system.
.IP "\fBmynetworks (see 'postconf -d' output)\fR"
The UNIX system account that owns the Postfix queue and most Postfix
daemon processes.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBrelocated_maps (empty)\fR"
Optional lookup tables with new contact information for users or
domains that no longer exist.
The time limit for sending or receiving information over an internal
communication channel.
.IP "\fBmax_idle (100s)\fR"
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting.
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily.
.IP "\fBmax_use (100)\fR"
-The maximal number of connection requests before a Postfix daemon
-process terminates.
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily.
.IP "\fBprocess_id (read-only)\fR"
The process ID of a Postfix command or daemon process.
.IP "\fBprocess_name (read-only)\fR"
<h2>Purpose of this document </h2>
-<p> This document describes the qshape(1) program which helps the
-administrator understand the Postfix queue message distribution
-sorted by time and by sender or recipient domain. qshape(1) is
-bundled with the Postfix 2.1 source under the "auxiliary" directory.
-</p>
-
-<p> In order to understand the output of qshape(1), it useful to
-understand the various Postfix queues. To this end the role of each
-Postfix queue directory is described briefly in the "Background
-info: Postfix queue directories" section near the end of this
-document. </p>
+<p> This document is an introduction to Postfix queue congestion analysis.
+It explains how the qshape(1) program can help to track down the
+reason for queue congestion. qshape(1) is bundled with Postfix
+2.1 and later source code, under the "auxiliary" directory. This
+document describes qshape(1) as bundled with Postfix 2.4. </p>
<p> This document covers the following topics: </p>
<li><a href="#backlog">Example 4: High volume destination backlog</a>
-<li><a href="#queues">Background info: Postfix queue directories</a>
+<li><a href="#queues">Postfix queue directories</a>
<ul>
<h2><a name="qshape">Introducing the qshape tool</a></h2>
-
<p> When mail is draining slowly or the queue is unexpectedly large,
run qshape(1) as the super-user (root) to help zero in on the problem.
The qshape(1) program displays a tabular view of the Postfix queue
</ul>
+<p> When the output is a terminal intermediate results showing the top 20
+domains (-n option) are displayed after every 1000 messages (-N option)
+and the final output also shows only the top 20 domains. This makes
+qshape useful even when the deferred queue is very large and it may
+otherwise take prohibitively long to read the entire deferred queue. </p>
+
<p> By default, qshape shows statistics for the union of both the
incoming and active queues which are the most relevant queues to
look at when analyzing performance. </p>
<blockquote>
<pre>
-$ qshape deferred | less
-$ qshape incoming active deferred | less
+$ qshape deferred
+$ qshape incoming active deferred
</pre>
</blockquote>
<p> The problem destinations or sender domains appear near the top
left corner of the output table. Remember that the active queue
can accommodate up to 20000 ($qmgr_message_active_limit) messages.
-To check wether this limit has been reached, use: </p>
+To check whether this limit has been reached, use: </p>
<blockquote>
<pre>
-$ qshape -s active | head <i>(show sender statistics)</i>
+$ qshape -s active <i>(show sender statistics)</i>
</pre>
</blockquote>
not yet saturated, any high volume sender domains show near the
top of the output.
-<p> The active queue is also limited to at most 20000 recipient
-addresses ($qmgr_message_recipient_limit). To check for exhaustion
-of this limit use: </p>
+<p> With oqmgr(8) the active queue is also limited to at most 20000
+recipient addresses ($qmgr_message_recipient_limit). To check for
+exhaustion of this limit use: </p>
<blockquote>
<pre>
-$ qshape active | head <i>(show recipient statistics)</i>
+$ qshape active <i>(show recipient statistics)</i>
</pre>
</blockquote>
take measures to ensure that the mail is deferred instead or even
add an access(5) rule asking the sender to try again later. </p>
-<p> If a high volume destination exhibits frequent bursts of
-consecutive connections refused by all MX hosts or "421 Server busy
-errors", it is possible for the queue manager to mark the destination
-as "dead" despite the transient nature of the errors. The destination
-will be retried again after the expiration of a $minimal_backoff_time
-timer. If the error bursts are frequent enough it may be that only
-a small quantity of email is delivered before the destination is
-again marked "dead". </p>
+<p> If a high volume destination exhibits frequent bursts of consecutive
+connections refused by all MX hosts or "421 Server busy errors", it
+is possible for the queue manager to mark the destination as "dead"
+despite the transient nature of the errors. The destination will be
+retried again after the expiration of a $minimal_backoff_time timer.
+If the error bursts are frequent enough it may be that only a small
+quantity of email is delivered before the destination is again marked
+"dead". In some cases enabling static (not on demand) connection
+caching by listing the appropriate nexthop domain in a table included in
+"smtp_connection_cache_destinations" may help to reduce the error rate,
+because most messages will re-use existing connections. </p>
<p> The MTA that has been observed most frequently to exhibit such
bursts of errors is Microsoft Exchange, which refuses connections
server propagate the refused connection to the client as a "421"
error. </p>
-<p> Note that it is now possible to configure Postfix to exhibit
-similarly erratic behavior by misconfiguring the anvil(8) server
-(not included in Postfix 2.1.). Do not use anvil(8) for steady-state
-rate limiting, its purpose is DoS prevention and the rate limits
-set should be very generous! </p>
+<p> Note that it is now possible to configure Postfix to exhibit similarly
+erratic behavior by misconfiguring the anvil(8) service. Do not use
+anvil(8) for steady-state rate limiting, its purpose is (unintentional)
+DoS prevention and the rate limits set should be very generous! </p>
-<p> In the long run it is hoped that the Postfix dead host detection
-and concurrency control mechanism will be tuned to be more "noise"
-tolerant. If one finds oneself needing to deliver a high volume
-of mail to a destination that exhibits frequent brief bursts of
-errors, there is a subtle workaround. </p>
+<p> If one finds oneself needing to deliver a high volume of mail to a
+destination that exhibits frequent brief bursts of errors and connection
+caching does not solve the problem, there is a subtle workaround. </p>
<ul>
transport (a number in the 10-20 range is typical). </p>
<li> <p> IMPORTANT!!! In main.cf configure a very large initial
-and destination concurrency limit for this transport (say 200). </p>
+and destination concurrency limit for this transport (say 2000). </p>
<pre>
/etc/postfix/main.cf:
- initial_destination_concurrency = 200
- <i>transportname</i>_destination_concurrency_limit = 200
+ initial_destination_concurrency = 2000
+ <i>transportname</i>_destination_concurrency_limit = 2000
</pre>
<p> Where <i>transportname</i> is the name of the master.cf entry
</ul>
-<p> The effect of this surprising configuration is that up to 200
+<p> The effect of this surprising configuration is that up to 2000
consecutive errors are tolerated without marking the destination
dead, while the total concurrency remains reasonable (10-20
processes). This trick is only for a very specialized situation:
high volume delivery into a channel with multi-error bursts
that is capable of high throughput, but is repeatedly throttled by
-the bursts of errors.
+the bursts of errors. </p>
<p> When a destination is unable to handle the load even after the
Postfix process limit is reduced to 1, a desperate measure is to
<p> Hopefully a more elegant solution to these problems will be
found in the future. </p>
-<h2><a name="queues">Background info: Postfix queue directories</a></h2>
+<h2><a name="queues">Postfix queue directories</a></h2>
<p> The following sections describe Postfix queues: their purpose,
what normal behavior looks like, and how to diagnose abnormal
<p> All mail that enters the main Postfix queue does so via the
cleanup(8) service. The cleanup service is responsible for envelope
and header rewriting, header and body regular expression checks,
-automatic bcc recipient processing and guaranteed insertion of the
-message into the Postfix "incoming" queue. </p>
+automatic bcc recipient processing, milter content processing, and
+reliable insertion of the message into the Postfix "incoming" queue. </p>
<p> In the absence of excessive CPU consumption in cleanup(8) header
or body regular expression checks or other software consuming all
disk I/O latency (+ CPU if not negligible) of the cleanup service.
</p>
-<p> Congestion in this queue is indicative of an excessive local
-message submission rate or perhaps excessive CPU consumption in
-the cleanup(8) service due to excessive body_checks. </p>
+<p> Congestion in this queue is indicative of an excessive local message
+submission rate or perhaps excessive CPU consumption in the cleanup(8)
+service due to excessive body_checks, or (Postfix ≥ 2.3) high latency
+milters. </p>
<p> Note, that once the active queue is full, the cleanup service
will attempt to slow down message injection by pausing $in_flow_delay
a consequence of congestion downstream, rather than a problem in
its own right. </p>
-<p> Note also, that one should not attempt to deliver large volumes
-of mail via the pickup(8) service. High volume sites must avoid
-using content filters that reinject scanned mail via Postfix
-sendmail(1) and postdrop(1). </p>
+<p> Note, you should not attempt to deliver large volumes of mail via
+the pickup(8) service. High volume sites should avoid using "simple"
+content filters that re-inject scanned mail via Postfix sendmail(1)
+and postdrop(1). </p>
<p> A high arrival rate of locally submitted mail may be an indication
of an uncaught forwarding loop, or a run-away notification program.
<p> The administrator can define "smtpd" access(5) policies, or
cleanup(8) header/body checks that cause messages to be automatically
diverted from normal processing and placed indefinitely in the
-"hold" queue. Messages placed in the "hold" queue stay there until
+"hold" queue. Messages placed in the "hold" queue stay there until
the administrator intervenes. No periodic delivery attempts are
made for messages in the "hold" queue. The postsuper(1) command
can be used to manually release messages into the "deferred" queue.
</p>
-<p> Messages can potentially stay in the "hold" queue for a time
-exceeding the normal maximal queue lifetime (after which undelivered
-messages are bounced back to the sender). If such "old" messages
-need to be released from the "hold" queue, they should typically
-be moved into the "maildrop" queue, so that the message gets a new
-timestamp and is given more than one opportunity to be delivered.
-Messages that are "young" can be moved directly into the "deferred"
-queue. </p>
+<p> Messages can potentially stay in the "hold" queue longer than
+$maximal_queue_lifetime. If such "old" messages need to be released from
+the "hold" queue, they should typically be moved into the "maildrop"
+queue using "postsuper -r", so that the message gets a new timestamp and
+is given more than one opportunity to be delivered. Messages that are
+"young" can be moved directly into the "deferred" queue using
+"postsuper -H". </p>
<p> The "hold" queue plays little role in Postfix performance, and
monitoring of the "hold" queue is typically more closely motivated
<p> The incoming queue grows when the message input rate spikes
above the rate at which the queue manager can import messages into
-the active queue. The main factor slowing down the queue manager
-is transport queries to the trivial-rewrite service. If the queue
+the active queue. The main factors slowing down the queue manager
+are disk I/O and lookup queries to the trivial-rewrite service. If the queue
manager is routinely not keeping up, consider not using "slow"
lookup services (MySQL, LDAP, ...) for transport lookups or speeding
-up the hosts that provide the lookup service. </p>
+up the hosts that provide the lookup service. If the problem is I/O
+starvation, consider striping the queue over more disks, faster controllers
+with a battery write cache, or other hardware improvements. At the very
+least, make sure that the queue directory is mounted with the "noatime"
+option if applicable to the underlying filesystem. </p>
<p> The in_flow_delay parameter is used to clamp the input rate
when the queue manager starts to fall behind. The cleanup(8) service
concurrency limit. </p>
<p> Multiple recipient groups (from one or more messages) are queued
-for delivery via the common transport/nexthop combination. The
-destination concurrency limit for the transports caps the number
+for delivery grouped by transport/nexthop combination. The
+<b>destination</b> concurrency limit for the transports caps the number
of simultaneous delivery attempts for each nexthop. Transports with
-a recipient concurrency limit of 1 are special: these are grouped
-by the actual recipient address rather than the nexthop, thereby
-enabling per-recipient concurrency limits rather than per-domain
+a <b>recipient</b> concurrency limit of 1 are special: these are grouped
+by the actual recipient address rather than the nexthop, yielding
+per-recipient concurrency limits rather than per-domain
concurrency limits. Per-recipient limits are appropriate when
performing final delivery to mailboxes rather than when relaying
to a remote server. </p>
<p> Congestion occurs in the active queue when one or more destinations
-drain slower than the corresponding message input rate. If a
-destination is down for some time, the queue manager will mark it
-dead, and immediately defer all mail for the destination without
+drain slower than the corresponding message input rate. </p>
+
+<p> Input into the active queue comes both from new mail in the "incoming"
+queue, and retries of mail in the "deferred" queue. Should the "deferred"
+queue get really large, retries of old mail can dominate the arrival
+rate of new mail. Systems with more CPU, faster disks and more network
+bandwidth can deal with larger deferred queues, but as a rule of thumb
+the deferred queue scales to somewhere between 100,000 and 1,000,000
+messages with good performance unlikely above that "limit". Systems with
+queues this large should typically stop accepting new mail, or put the
+backlog "on hold" until the underlying issue is fixed (provided that
+there is enough capacity to handle just the new mail). </p>
+
+<p> When a destination is down for some time, the queue manager will
+mark it dead, and immediately defer all mail for the destination without
trying to assign it to a delivery agent. In this case the messages
-will quickly leave the active queue and end up in the deferred
-queue. If the destination is instead simply slow, or there is a
-problem causing an excessive arrival rate the active queue will
-grow and will become dominated by mail to the congested destination.
-</p>
+will quickly leave the active queue and end up in the deferred queue
+(with Postfix < 2.4, this is done directly by the queue manager,
+with Postfix ≥ 2.4 this is done via the "retry" delivery agent). </p>
+
+<p> When the destination is instead simply slow, or there is a problem
+causing an excessive arrival rate the active queue will grow and will
+become dominated by mail to the congested destination. </p>
<p> The only way to reduce congestion is to either reduce the input
rate or increase the throughput. Increasing the throughput requires
is draining slowly and the system and network are not loaded, raise
the "smtp" and/or "relay" process limits! </p>
-<p> Especially for the "relay" transport, consider lower SMTP
-connection timeouts (1-5 seconds) and higher than default destination
-concurrency limits. Compute the expected latency when 1 out of N
-of the MX hosts for a high volume site is down and not responding,
-and make sure that the configured concurrency divided by this
-latency exceeds the required steady-state message rate. If the
-destination is managed by you, consider load balancers in front of
-groups of MX hosts. Load balancers have higher uptime and will be
-able to hide individual MX host failures. </p>
-
-<p> If necessary, dedicate and tune custom transports for high
-volume destinations. </p>
-
-<p> Another common cause of congestion is unwarranted flushing of
-the entire deferred queue. The deferred queue holds messages that
-are likely to fail to be delivered and are also likely to be slow
-to fail delivery (timeouts). This means that the most common reaction
-to a large deferred queue (flush it!) is more than likely counter-
-productive, and is likely to make the problem worse. Do not flush
-the deferred queue unless you expect that most of its content has
-recently become deliverable (e.g. relayhost back up after an outage)!
-</p>
+<p> When a high volume destination is served by multiple MX hosts with
+typically low delivery latency, performance can suffer dramatically when
+one of the MX hosts is unresponsive and SMTP connections to that host
+timeout. For example, if there are 2 equal weight MX hosts, the SMTP
+connection timeout is 30 seconds and one of the MX hosts is down, the
+average SMTP connection will take approximately 15 seconds to complete.
+With a default per-destination concurrency limit of 20 connections,
+throughput falls to just over 1 message per second. </p>
+
+<p> The best way to avoid bottlenecks when one or more MX hosts is
+non-responsive is to use connection caching. Connection caching was
+introduced with Postfix 2.2 and is by default enabled on demand for
+destinations with a backlog of mail in the active queue. When connection
+caching is in effect for a particular destination, established connections
+are re-used to send additional messages, this reduces the number of
+connections made per message delivery and maintains good throughput even
+in the face of partial unavailability of the destination's MX hosts. </p>
+
+<p> If connection caching is not available (Postfix < 2.2) or does
+not provide a sufficient latency reduction, especially for the "relay"
+transport used to forward mail to "your own" domains, consider setting
+lower than default SMTP connection timeouts (1-5 seconds) and higher
+than default destination concurrency limits. This will further reduce
+latency and provide more concurrency to maintain throughput should
+latency rise. </p>
+
+<p> Setting high concurrency limits to domains that are not your own may
+be viewed as hostile by the receiving system, and steps may be taken
+to prevent you from monopolizing the destination system's resources.
+The defensive measures may substantially reduce your throughput or block
+access entirely. Do not set aggressive concurrency limits to remote
+domains without coordinating with the administrators of the target
+domain. </p>
+
+<p> If necessary, dedicate and tune custom transports for selected high
+volume destinations. The "relay" transport is provided for forwarding mail
+to domains for which your server is a primary or backup MX host. These can
+make up a substantial fraction of your email traffic. Use the "relay" and
+not the "smtp" transport to send email to these domains. Using the "relay"
+transport allocates a separate delivery agent pool to these destinations
+and allows separate tuning of timeouts and concurrency limits. </p>
+
+<p> Another common cause of congestion is unwarranted flushing of the
+entire deferred queue. The deferred queue holds messages that are likely
+to fail to be delivered and are also likely to be slow to fail delivery
+(time out). As a result the most common reaction to a large deferred queue
+(flush it!) is more than likely counter-productive, and typically makes
+the congestion worse. Do not flush the deferred queue unless you expect
+that most of its content has recently become deliverable (e.g. relayhost
+back up after an outage)! </p>
<p> Note that whenever the queue manager is restarted, there may
already be messages in the active queue directory, but the "real"
the messages back and forth, redoing transport table (trivial-rewrite(8)
resolve service) lookups, and re-importing the messages back into
memory is expensive. At all costs, avoid frequent restarts of the
-queue manager. </p>
+queue manager (e.g. via frequent execution of "postfix reload"). </p>
<h3> <a name="deferred_queue"> The "deferred" queue </a> </h3>
might succeed later), the message is placed in the deferred queue.
</p>
-<p> The queue manager scans the deferred queue periodically. The
-scan interval is controlled by the queue_run_delay parameter.
-While a deferred queue scan is in progress, if an incoming queue
-scan is also in progress (ideally these are brief since the incoming
-queue should be short), the queue manager alternates between bringing
-a new "incoming" message and a new "deferred" message into the
-queue. This "round-robin" strategy prevents starvation of either
-the incoming or the deferred queues. </p>
+<p> The queue manager scans the deferred queue periodically. The scan
+interval is controlled by the queue_run_delay parameter. While a deferred
+queue scan is in progress, if an incoming queue scan is also in progress
+(ideally these are brief since the incoming queue should be short), the
+queue manager alternates between looking for messages in the "incoming"
+queue and in the "deferred" queue. This "round-robin" strategy prevents
+starvation of either the incoming or the deferred queues. </p>
<p> Each deferred queue scan only brings a fraction of the deferred
queue back into the active queue for a retry. This is because each
message in the deferred queue is assigned a "cool-off" time when
it is deferred. This is done by time-warping the modification
-times of the queue file into the future. The queue file is not
+time of the queue file into the future. The queue file is not
eligible for a retry if its modification time is not yet reached.
</p>
retried more often than old messages. </p>
<p> If a high volume site routinely has large deferred queues, it
-may be useful to adjust the queue_run_delay, minimal_backoff_time
-and maximal_backoff_time to provide short enough delays on first
-failure, with perhaps longer delays after multiple failures, to
-reduce the retransmission rate of old messages and thereby reduce
-the quantity of previously deferred mail in the active queue. </p>
+may be useful to adjust the queue_run_delay, minimal_backoff_time and
+maximal_backoff_time to provide short enough delays on first failure
+(Postfix ≥ 2.4 has a sensibly low minimal backoff time by default),
+with perhaps longer delays after multiple failures, to reduce the
+retransmission rate of old messages and thereby reduce the quantity
+of previously deferred mail in the active queue. If you want a really
+low minimal_backoff_time, you may also want to lower queue_run_delay,
+but understand that more frequent scans will increase the demand for
+disk I/O. </p>
<p> One common cause of large deferred queues is failure to validate
recipients at the SMTP input stage. Since spammers routinely launch
dictionary attacks from unrepliable sender addresses, the bounces
-for invalid recipient addresses clog the deferred queue (and at
-high volumes proportionally clog the active queue). Recipient
-validation is strongly recommended through use of the local_recipient_maps
-and relay_recipient_maps parameters. </p>
+for invalid recipient addresses clog the deferred queue (and at high
+volumes proportionally clog the active queue). Recipient validation
+is strongly recommended through use of the local_recipient_maps and
+relay_recipient_maps parameters. Even when bounces drain quickly they
+inundate innocent victims of forgery with unwanted email. To avoid
+this, do not accept mail for invalid recipients. </p>
<p> When a host with lots of deferred mail is down for some time,
it is possible for the entire deferred queue to reach its retry
time simultaneously. This can lead to a very full active queue once
the host comes back up. The phenomenon can repeat approximately
every maximal_backoff_time seconds if the messages are again deferred
-after a brief burst of congestion. Ideally, in the future Postfix
+after a brief burst of congestion. Perhaps, a future Postfix release
will add a random offset to the retry time (or use a combination
-of strategies) to reduce the chances of repeated complete deferred
+of strategies) to reduce the odds of repeated complete deferred
queue flushes. </p>
<h2><a name="credits">Credits</a></h2>
# NAME
# access 5
# SUMMARY
-# Postfix access table format
+# Postfix SMTP server access table
# SYNOPSIS
# \fBpostmap /etc/postfix/access\fR
#
#
# \fBpostmap -q - /etc/postfix/access <\fIinputfile\fR
# DESCRIPTION
-# The optional \fBaccess\fR(5) table directs the Postfix SMTP server
-# to selectively reject or accept mail. Access can be allowed or
-# denied for specific host names, domain names, networks, host
-# addresses or mail addresses.
-#
-# For an example, see the EXAMPLE section at the end of this
-# manual page.
+# The Postfix SMTP server \fBaccess\fR(5) table specifies
+# actions that are triggered by information from or about
+# remote SMTP clients: host names, network addresses, or email
+# addresses. An action may grant or deny access, or it may
+# change the way that an email transaction will be handled.
#
# Normally, the \fBaccess\fR(5) table is specified as a text file
# that serves as input to the \fBpostmap\fR(1) command.
# The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
-# is used for fast searching by the mail system. Execute the command
-# "\fBpostmap /etc/postfix/access\fR" in order to rebuild the indexed
-# file after changing the access table.
+# is used for fast searching by the mail system. Execute the
+# command "\fBpostmap /etc/postfix/access\fR" to rebuild an
+# indexed file after changing the corresponding text file.
#
# When the table is provided via other means such as NIS, LDAP
# or SQL, the same lookups are done as for ordinary indexed files.
#
# Alternatively, the table can be provided as a regular-expression
# map where patterns are given as regular expressions, or lookups
-# can be directed to TCP-based server. In that case, the lookups are
-# done in a slightly different way as described below under
-# "REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+# can be directed to TCP-based server. In those cases, the lookups
+# are done in a slightly different way as described below under
+# "REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
# CASE FOLDING
# .ad
# .fi
# This feature is available in Postfix 2.0 and later.
# .IP "\fBPREPEND \fIheadername: headervalue\fR"
# Prepend the specified message header to the message.
-# When this action is used multiple times, the first prepended
+# When this action executes multiple times, the first prepended
# header appears before the second etc. prepended header.
# .sp
# Note: this action does not support multi-line message headers.
# .sp
-# Note: this action must be used before the message content
-# is received; it cannot be used in \fBsmtpd_end_of_data_restrictions\fR.
+# Note: this action must execute before the message content
+# is received; it cannot execute in the context of
+# \fBsmtpd_end_of_data_restrictions\fR.
# .sp
# This feature is available in Postfix 2.1 and later.
# .IP "\fBREDIRECT \fIuser@domain\fR"
# that serves as input to the \fBpostmap\fR(1) command.
# The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
# is used for fast searching by the mail system. Execute the command
-# "\fBpostmap /etc/postfix/canonical\fR" in order to rebuild the indexed
-# file after changing the text file.
+# "\fBpostmap /etc/postfix/canonical\fR" to rebuild an indexed
+# file after changing the corresponding text file.
#
# When the table is provided via other means such as NIS, LDAP
# or SQL, the same lookups are done as for ordinary indexed files.
#
# Alternatively, the table can be provided as a regular-expression
# map where patterns are given as regular expressions, or lookups
-# can be directed to TCP-based server. In that case, the lookups are
-# done in a slightly different way as described below under
-# "REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+# can be directed to TCP-based server. In those cases, the lookups
+# are done in a slightly different way as described below under
+# "REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
#
# By default the \fBcanonical\fR(5) mapping affects both message
# header addresses (i.e. addresses that appear inside messages)
# The Postfix mail system uses optional lookup tables.
# These tables are usually in \fBdbm\fR or \fBdb\fR format.
# Alternatively, lookup tables can be specified in CIDR
-# (Classless Inter-Domain Routing) form.
+# (Classless Inter-Domain Routing) form. In this case, each
+# input is compared against a list of patterns. When a match
+# is found, the corresponding result is returned and the search
+# is terminated.
#
# To find out what types of lookup tables your Postfix system
# supports use the "\fBpostconf -m\fR" command.
# command. The result, an indexed file in \fBdbm\fR or
# \fBdb\fR format, is used for fast searching by the mail
# system. Execute the command "\fBpostmap /etc/postfix/generic\fR"
-# in order to rebuild the indexed file after changing the
+# to rebuild an indexed file after changing the corresponding
# text file.
#
# When the table is provided via other means such as NIS, LDAP
#
# Alternatively, the table can be provided as a regular-expression
# map where patterns are given as regular expressions, or lookups
-# can be directed to TCP-based server. In that case, the lookups are
-# done in a slightly different way as described below under
-# "REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+# can be directed to TCP-based server. In those case, the lookups
+# are done in a slightly different way as described below under
+# "REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
# CASE FOLDING
# .ad
# .fi
#
# Alternatively, lookup tables can be specified in Perl Compatible
# Regular Expression form. In this case, each input is compared
-# against a list of patterns, and when a match is found the
-# corresponding result is returned.
+# against a list of patterns. When a match is found, the
+# corresponding result is returned and the search is terminated.
#
# To find out what types of lookup tables your Postfix system
# supports use the "\fBpostconf -m\fR" command.
%PARAM max_idle 100s
<p>
-The maximum amount of time that an idle Postfix daemon process
-waits for the next service request before exiting. This parameter
+The maximum amount of time that an idle Postfix daemon process waits
+for an incoming connection before terminating voluntarily. This
+parameter
is ignored by the Postfix queue manager and by other long-lived
Postfix daemon processes.
</p>
%PARAM max_use 100
<p>
-The maximal number of connection requests before a Postfix daemon
-process terminates. This parameter is ignored by the Postfix queue
+The maximal number of incoming connections that a Postfix daemon
+process will service before terminating voluntarily. This parameter
+is ignored by the Postfix queue
manager and by other long-lived Postfix daemon processes.
</p>
<ul>
-<li> a = time before the queue manager, including message transmission
+<li> a = time from message arrival to last active queue entry
-<li> b = time in queue manager
+<li> b = time from last active queue entry to connection setup
<li> c = time in connection setup, including DNS, EHLO and TLS
<p> This feature is available in Postfix 2.3 and later. </p>
-%PARAM lmtp_discard_lhlo_keywords $myhostname
+%PARAM lmtp_discard_lhlo_keywords
<p> A case insensitive list of LHLO keywords (pipelining, starttls,
auth, etc.) that the LMTP client will ignore in the LHLO response
#
# Alternatively, lookup tables can be specified in POSIX regular
# expression form. In this case, each input is compared against a
-# list of patterns, and when a match is found the corresponding
-# result is returned.
+# list of patterns. When a match is found, the corresponding
+# result is returned and the search is terminated.
#
# To find out what types of lookup tables your Postfix system
# supports use the "\fBpostconf -m\fR" command.
# that serves as input to the \fBpostmap\fR(1) command.
# The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
# is used for fast searching by the mail system. Execute the command
-# "\fBpostmap /etc/postfix/relocated\fR" in order to rebuild the indexed
-# file after changing the relocated table.
+# "\fBpostmap /etc/postfix/relocated\fR" to rebuild an indexed
+# file after changing the corresponding relocated table.
#
# When the table is provided via other means such as NIS, LDAP
# or SQL, the same lookups are done as for ordinary indexed files.
#
# Alternatively, the table can be provided as a regular-expression
# map where patterns are given as regular expressions, or lookups
-# can be directed to TCP-based server. In that case, the lookups are
-# done in a slightly different way as described below under
-# "REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+# can be directed to TCP-based server. In those case, the lookups
+# are done in a slightly different way as described below under
+# "REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
#
# Table lookups are case insensitive.
# CASE FOLDING
# that serves as input to the \fBpostmap\fR(1) command.
# The result, an indexed file in \fBdbm\fR or \fBdb\fR format, is used
# for fast searching by the mail system. Execute the command
-# "\fBpostmap /etc/postfix/transport\fR" in order to rebuild the indexed
-# file after changing the transport table.
+# "\fBpostmap /etc/postfix/transport\fR" to rebuild an indexed
+# file after changing the corresponding transport table.
#
# When the table is provided via other means such as NIS, LDAP
# or SQL, the same lookups are done as for ordinary indexed files.
#
# Alternatively, the table can be provided as a regular-expression
# map where patterns are given as regular expressions, or lookups
-# can be directed to TCP-based server. In that case, the lookups are
-# done in a slightly different way as described below under
-# "REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+# can be directed to TCP-based server. In those case, the lookups
+# are done in a slightly different way as described below under
+# "REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
# CASE FOLDING
# .ad
# .fi
# that serves as input to the \fBpostmap\fR(1) command.
# The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
# is used for fast searching by the mail system. Execute the command
-# "\fBpostmap /etc/postfix/virtual\fR" in order to rebuild the indexed
-# file after changing the text file.
+# "\fBpostmap /etc/postfix/virtual\fR" to rebuild an indexed
+# file after changing the corresponding text file.
#
# When the table is provided via other means such as NIS, LDAP
# or SQL, the same lookups are done as for ordinary indexed files.
#
# Alternatively, the table can be provided as a regular-expression
# map where patterns are given as regular expressions, or lookups
-# can be directed to TCP-based server. In that case, the lookups are
-# done in a slightly different way as described below under
-# "REGULAR EXPRESSION TABLES" and "TCP-BASED TABLES".
+# can be directed to TCP-based server. In those case, the lookups
+# are done in a slightly different way as described below under
+# "REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES".
# CASE FOLDING
# .ad
# .fi
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The mail system name that is displayed in Received: headers, in
/* the SMTP greeting banner, and in bounced mail.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBnotify_classes (resource, software)\fR"
/* The list of error classes that are reported to the postmaster.
/* .IP "\fBprocess_id (read-only)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBmyhostname (see 'postconf -d' output)\fR"
/* The internet hostname of this mail system.
/* .IP "\fBmyorigin ($myhostname)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The Postfix \fBerror\fR(8) delivery agent processes delivery
/* requests from
/* the queue manager. Each request specifies a queue file, a sender
-/* address, a domain or host name that is treated as the reason for
-/* non-delivery, and recipient information.
+/* address, the reason for non-delivery (specified as the
+/* next-hop destination), and recipient information.
/* The reason may be prefixed with an RFC 3463-compatible detail code.
/* This program expects to be run from the \fBmaster\fR(8) process
/* manager.
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBnotify_classes (resource, software)\fR"
/* The list of error classes that are reported to the postmaster.
/* .IP "\fBprocess_id (read-only)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBparent_domain_matches_subdomains (see 'postconf -d' output)\fR"
/* What Postfix features match subdomains of "domain.tld" automatically,
/* instead of requiring an explicit ".domain.tld" pattern.
* patchlevel; they change the release date only.
*/
#define MAIL_RELEASE_DATE "20070306"
-#define MAIL_VERSION_NUMBER "2.4.0-RC3"
+#define MAIL_VERSION_NUMBER "2.4.0-RC4"
#ifdef SNAPSHOT
# define MAIL_VERSION_DATE "-" MAIL_RELEASE_DATE
/* .IP "\fBlocal_command_shell (empty)\fR"
/* Optional shell program for \fBlocal\fR(8) delivery to non-Postfix command.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprepend_delivered_header (command, file, forward)\fR"
/* The message delivery contexts where the Postfix \fBlocal\fR(8) delivery
/* agent prepends a Delivered-To: message header with the address
/* The default maximal number of Postfix child processes that provide
/* a given service.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBservice_throttle_time (60s)\fR"
/* How long the Postfix \fBmaster\fR(8) waits before forking a server that
/* appears to be malfunctioning.
/* Upon input, long lines are chopped up into pieces of at most
/* this length; upon delivery, long lines are reconstructed.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The UNIX system account that owns the Postfix queue and most Postfix
/* daemon processes.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/*
/* By default, connection caching is enabled temporarily for
/* destinations that have a high volume of mail in the active
-/* queue. Session caching can be enabled permanently for
+/* queue. Connection caching can be enabled permanently for
/* specific destinations.
/* SMTP DESTINATION SYNTAX
/* .ad
/* case insensitive lists of LHLO keywords (pipelining, starttls,
/* auth, etc.) that the LMTP client will ignore in the LHLO response
/* from a remote LMTP server.
-/* .IP "\fBlmtp_discard_lhlo_keywords ($myhostname)\fR"
+/* .IP "\fBlmtp_discard_lhlo_keywords (empty)\fR"
/* A case insensitive list of LHLO keywords (pipelining, starttls,
/* auth, etc.) that the LMTP client will ignore in the LHLO response
/* from a remote LMTP server.
/* .IP "\fBlmtp_tcp_port (24)\fR"
/* The default TCP port that the Postfix LMTP client connects to.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The UNIX system account that owns the Postfix queue and most Postfix
/* daemon processes.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBmyhostname (see 'postconf -d' output)\fR"
/* The internet hostname of this mail system.
/* .IP "\fBmynetworks (see 'postconf -d' output)\fR"
/* The UNIX system account that owns the Postfix queue and most Postfix
/* daemon processes.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBrelocated_maps (empty)\fR"
/* Optional lookup tables with new contact information for users or
/* domains that no longer exist.
/* The time limit for sending or receiving information over an internal
/* communication channel.
/* .IP "\fBmax_idle (100s)\fR"
-/* The maximum amount of time that an idle Postfix daemon process
-/* waits for the next service request before exiting.
+/* The maximum amount of time that an idle Postfix daemon process waits
+/* for an incoming connection before terminating voluntarily.
/* .IP "\fBmax_use (100)\fR"
-/* The maximal number of connection requests before a Postfix daemon
-/* process terminates.
+/* The maximal number of incoming connections that a Postfix daemon
+/* process will service before terminating voluntarily.
/* .IP "\fBprocess_id (read-only)\fR"
/* The process ID of a Postfix command or daemon process.
/* .IP "\fBprocess_name (read-only)\fR"
projects / thirdparty / postfix.git / commitdiff
