I'm a happy SpamAssassin user too, just wanted to add that I've found using sa-learn to teach it about ham/spam makes the spam detection a lot better. When spam

I'm a happy SpamAssassin user too, just wanted to add that I've found using sa-learn to teach it about ham/spam makes the spam detection a lot better. When spam gets through, I move it to a junk folder, and from time to time, use that folder to train SA on. The level of false positives is tiny, perhaps 1-2 emails a year.