MacOS X Spam Fighting

I've been seriously bummed that I've been unable to implement the latest new antispam tricks since I'm on MacOS X and I'm basically stuck with Mail.app's plain vanilla spam filters. I used to maintain a tip sheet on spam filtering for MacOS X using procmail and SpamBouncer, but that technique was obsoleted in MacOS X 10.2 when Apple removed Mail.app's support for unix mbox format. The only way to use to procmail filtering with MacOS X was to set up your own mail server, I'd rather not bother with that. But now I'm all excited that someone figured out how to add mbox support back into Mail.app. I'm going to give it a whirl and see if I can't patch together some new spam filtering tricks, maybe I'll try SpamAssassin instead of Spambouncer.