If the file listdir/control/access is present, access control is enabled.
NOTE: the default action is to deny access (reject the mail), so an empty access control file will cause mlmmj to reject all posts, whereas a non-existant file will change nothing, and mlmmj will behave as usual.
Each header in the mail is tested against each rule, rule by rule. That is, all headers are first tested against the first rule, then all headers are tested against the second rule, and so on.
The first rule to match a header decides which action to take - allow, deny or moderate the post.
The syntax is quite simple:
action[ [!]regexp]
IMPORTANT: if "moderate" is used then don't forget to add people who should function as moderators in listdir/control/moderators
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