The flow through the access system is something like this:
+````
deny +------+
+----------------->| deny |
| +------+
| +--------------+ |
| send |
+------------------------------------------+
+````
* modnonsubposts is also processed here, and subonlypost (the flow
may be to deny or discard for subonlypost without modnonsubposts).
First a simple example. This rule set will reject any mail that is NOT plain
text, or has a subject that contains "BayStar", and allow anything else:
+````
deny !^Content-Type: text/plain
deny ^Subject:.*BayStar
allow
+````
To allow only text mails, but have the moderators moderate every html mail one
would use this:
+````
allow ^Content-Type: text/plain
moderate ^Content-Type: text/html
deny
+````
Now on to a more advanced example. Morten can post anything, Mads Martin can
post if the subject does not contain "SCO". Everything else is denied:
+````
allow ^From: Morten
deny ^Subject:.*SCO
allow ^From: Mads Martin
deny
+````
The last rule (deny) can be left out, as deny is the default action.
A third example. Deny any mails with "discount", "weightloss", or "bonus" in
the subject. Allow PGP signed and plain text mails. Anything else is denied:
+````
deny ^Subject:.*discount
deny ^Subject:.*weightloss
deny ^Subject:.*bonus
allow ^Content-Type: multipart/signed
allow ^Content-Type: text/plain
+````