Security: the Postfix SMTP server by default disconnects remote
SMTP clients that violate RFC 2920 (or 5321) command pipelining
-constraints. The server replies with "421 4.7.0 Error: SMTP protocol
+constraints. The server replies with "554 5.5.0 Error: SMTP protocol
synchronization" and logs the unexpected remote SMTP client input.
Specify "smtpd_reject_unauth_pipelining = no" to disable.
(default: Postfix ≥ 3.9: yes)</b></DT><DD>
<p> Disconnect remote SMTP clients that violate <a href="https://tools.ietf.org/html/rfc2920">RFC 2920</a> (or 5321)
-command pipelining constraints. The server replies with "421 4.7.0
+command pipelining constraints. The server replies with "554 5.5.0
Error: SMTP protocol synchronization" and logs the unexpected remote
SMTP client input. This feature is enabled by default with Postfix
≥ 3.9. Specify "<a href="postconf.5.html#smtpd_forbid_unauth_pipelining">smtpd_forbid_unauth_pipelining</a> = no" to disable.
</p>
-<p> This feature is available in Postfix 3.9 ≥ 3.9, 3.8.1, 3.7.6,
+<p> This feature is available in Postfix ≥ 3.9, 3.8.1, 3.7.6,
3.6.10, and 3.5.20. </p>
This feature is available in Postfix 2.0 and later.
.SH smtpd_forbid_unauth_pipelining (default: Postfix >= 3.9: yes)
Disconnect remote SMTP clients that violate RFC 2920 (or 5321)
-command pipelining constraints. The server replies with "421 4.7.0
+command pipelining constraints. The server replies with "554 5.5.0
Error: SMTP protocol synchronization" and logs the unexpected remote
SMTP client input. This feature is enabled by default with Postfix
>= 3.9. Specify "smtpd_forbid_unauth_pipelining = no" to disable.
.PP
-This feature is available in Postfix 3.9 >= 3.9, 3.8.1, 3.7.6,
+This feature is available in Postfix >= 3.9, 3.8.1, 3.7.6,
3.6.10, and 3.5.20.
.SH smtpd_forbidden_commands (default: CONNECT GET POST regexp:{{/^[^A\-Z]/ Bogus}})
List of commands that cause the Postfix SMTP server to immediately
%PARAM smtpd_forbid_unauth_pipelining Postfix ≥ 3.9: yes
<p> Disconnect remote SMTP clients that violate RFC 2920 (or 5321)
-command pipelining constraints. The server replies with "421 4.7.0
+command pipelining constraints. The server replies with "554 5.5.0
Error: SMTP protocol synchronization" and logs the unexpected remote
SMTP client input. This feature is enabled by default with Postfix
≥ 3.9. Specify "smtpd_forbid_unauth_pipelining = no" to disable.
</p>
-<p> This feature is available in Postfix 3.9 ≥ 3.9, 3.8.1, 3.7.6,
+<p> This feature is available in Postfix ≥ 3.9, 3.8.1, 3.7.6,
3.6.10, and 3.5.20. </p>
* Patches change both the patchlevel and the release date. Snapshots have no
* patchlevel; they change the release date only.
*/
-#define MAIL_RELEASE_DATE "20230603"
+#define MAIL_RELEASE_DATE "20230605"
#define MAIL_VERSION_NUMBER "3.9"
#ifdef SNAPSHOT
&& smtpd_flag_ill_pipelining(state)
&& var_smtpd_forbid_unauth_pipe) {
smtpd_chat_reply(state,
- "421 4.7.0 Error: SMTP protocol synchronization");
+ "554 5.5.0 Error: SMTP protocol synchronization");
break;
}
&& smtpd_flag_ill_pipelining(state)
&& var_smtpd_forbid_unauth_pipe) {
smtpd_chat_reply(state,
- "421 4.7.0 Error: SMTP protocol synchronization");
+ "554 5.5.0 Error: SMTP protocol synchronization");
break;
}
if (cmdp->action(state, argc, argv) != 0)