(postfix) SPAM filter?

[Chuck Swiger]

On Dec 12, 2007, at 5:12 PM, Sten Daniel Soersdal wrote:
> We have a need for a relatively painless anti-spam solution that  
> would reduce the amount of incoming spam (via postfix mail router).  
> The problem is that i have little knowledge on what this actually  
> means. Googling reveals a whole "universe" of interesting ways but  
> what should i pursue?
> The things that are important to me is:
>
> * Once it is setup then it would require no additional maintenance.
> * Potential spam messages are marked with a special header that can  
> be filtered on user discretion on their local mail client software.

Install the following:

/usr/ports/mail/postfix-policyd-weight
/usr/ports/mail/postgrey
/usr/ports/mail/p5-Mail-SpamAssassin
/usr/ports/security/amavisd-new
/usr/ports/security/clamav

policyd + postgrey provide rather good, very lightweight initial  
filtering of email without taking up a lot of memory or resources, and  
remove a lot of workload, so that the Amavisd+ClamAV+SA combination  
only has to do virus-scanning and SpamAssassin's expensive Bayesian  
word-mangling on emails which seem to be legit.

Regards,
-- 
-Chuck