Server-side Spam Control Software?

So I’ve been asked to find us some sort of SPAM control software that can be resident on our mail server.

Can anyone point me in a good direction? Anyone had any experience with such?

Our Linux email server has 6 anti-spam programs on it. All of them rely use lists of domains. I think all of them are totally free.

Spamcop
Open Relay Database
Distributed Server Boycott List
SORBS
MAPS RBL

My ISP uses SpamAssassin, which seems to work pretty well.

Blacklists (like the last 3 mblackwell lists) are well known to have bad effects – lots of false positives, and can prevent a whole lot of legitimate email from reaching you. Commonly referred to as the “using a sledgehammer on a mosquito” approach. I’d try to avoid them.

The best anti-SPAM software is the Bayseian-type filters. But those have to be on individual PC’s, not server-based. The whole point is that they are personal, and filter out email not relevant to that individual person. It’s hard to make that work at a server level, for a whole lot of different persons.

http://www.brightmail.com/ is the 600 pound gorilla that we use.

http://www.spamcop.net/ isn’t only server-side, they also help play a crucial role in the spamfighting cause: pre-processing of spam reports for today’s lazy and technically ignorant internet users.

Investigating the relevant, clear, concise evidence that spamcop submits in an abuse complaint…is like a cool sip of water in the vast desert of half-baked, misdirected crap thrown at us by the clueless.