Over the years I've pretty much used every anti-spam measure in existence. The only one I've found that actually works (and it is pretty much faultless, 100+ spams caught daily, 0 false positives!) is SpamNet, this has recently become pay-ware ($3.99 a month or $1.99 if you were a beat tester). I have recently bought two subscriptions (work and home). It really is worth it...go on! http://www.cloudmark.com.