james28909,

Have you tried MailScanner? (It's written in Perl)

I have fought spam since 1997, and at one time we were receiving more than 1,000,000 spams per day per mail server, 7 days a week. I started using MailScanner and it worked perfectly for about the first 2 years, and then it seemed to max-out handling about 30K emails per day. We wrote a pre-processor with Perl looking for the obvious spam finger-prints and we have held our own ever since.

Perl's 'index' function saved the day. Using 'index' and known spam lists developed by us, we could keep up with 1MM spams on a single core server. We use multi-core servers now, so we have plenty of capacity.

You don't mention numbers, so my comments are for sizing consideration. YMMV

Good Luck!

Regards...Ed