The mailing list for listmasters using Sympa

[Cefiar <address@concealed>]

On Tuesday 17 October 2006 01:10, Dilyan Palauzov wrote:
>    Next, implement Sieve in a MTA. I personally would like to create a
> sendmail filter (sieve-milter) that does the job, based on the sieve
> implementation in cyrus-imap. To my knowledge, at the moment only exim
> as MTA offers partly support for Sieve
> (http://exim.netmirror.org/exim-html-4.30/doc/html/filter_2.html)
> however without the ability to not-accept mails.

Postfix has it's "Postfix policy delegation protocol". This is used for 
things 
like implementing greylisting or other policy systems during the receiving 
process. This sort of system may be better for this than a milter.

I was thinking of playing with this to implement greylisting from addresses 
that are not subscribed to the receiving list or on the list of allowed 
posters. Since people who are on the list (or that meet some other policy 
decision, such as moderator only posting, etc) get allowed immediately, there 
is no delay for most list mail. The only time there is a delay is if the 
message doesn't meet the allowed criteria. Since MANY (not all) spammers and 
virii don't bother to retry, this can reduce them both like ordinary 
greylisting does. The message can even be rejected at this point if there is 
no option for moderation for the list.

Policy Services and the protocol that postfix and the client talk to each 
other with is documented at: http://www.postfix.org/SMTPD_POLICY_README.html

Note: I haven't the time to do anything on this at the moment. Sorry. If 
anyone wants to take the idea and fly with it, go for it!

-- 
 Stuart Young - aka Cefiar - address@concealed