I’ve added Deersoft’s SpamAssassin Pro to my arsenal of spam defenses, which also includes the freeware Unix version of SpamAssassin, Brightmail, Cloudmark’s SpamNet, and two layers of hand-crafted filters. The false-positive rate is still higher than I’d like, primarily due to the Unix SpamAssassin. Most of the false positives are legitimate mass commercial email that I’ve signed up for, but it mistakenly sweeps in about one personal message per week. When I have time I should be able to tweak those filters to be more accurate.
The good news is that I’m down to roughly five spams per day that run the gauntlet and must be deleted manually. SpamAssassin alone is catching about 250 daily. Interestingly, SpamAssassin Pro kicks out two or three spams per day that my Unix SpamAssassin lets through. Cloudmark gets another three or four.
My setup may sound like overkill, but I don’t see how email would be usable without it. I’d be spending most of my day deleting spam, looking for the legitimate messages.