[Dovecot] Unoffical Survey - What MTA/Spam filtering do you use?

[Marc Perkel]

I'm basically trying to use every trick out there. Here's a detailed 
explation of everything I'm doing:

http://www.junkemailfilter.com/spam/how_it_works.html

Mostly I'm using Exim rules and Spamassassin. Exim allws me to do whost 
all the front end tricks like sender verification and blacklist lookup 
and I'm eliminating 90% of spam before I even get to spamassassin. Then 
I use Exim again to do the fancy routing that many people use Sieve for.

I'm processing about 1.2 million email attempts per day and passing 
50,000 good messages on. And most all of it with a single computer 
that's a Dual Core Athlon 3800 with 4 gigs of ram.

But I'm always looking for new tricks.