Outlook Spam Filter is an easy-to-use MS Outlook add-on that protects your Inbox against spam. The program is based on Bayesian filtering technology. It automatically learns using your personal correspondence to increase the filtration accuracy. Quarantined e-mails are stored in a separate SPAM folder. Users can manage their friends and enemies lists or build their own filters. The program has an option to test outgoing mail for potential risk of being filtered as spam. Recognition of newsgroup messages using Safe Recipients list and automatic inclusion of outgoing mail recipients into Friends List are available. POP3, IMAP, HTTP and MS Exchange support.
I'm an experienced user spam filter user. I used to use Outlook Spam Filter, SpamInspector, plus used SpamArrest (online server) to add a challenge email step to one of my accounts...
recently I discovered another filter at http://www.spambully.com.
SpamBully was rated BEST BUY in October 2003 WIRED Magazine:
http://www.wired.com/wired/archive/11.10/play.html?pg=10
I have downloaded trial, and love it!
SpamBully does it all - I have even been able to delete all of my old, manually entered spam-filtering rules - the Bayesian wizard is phenominal out-of-the-box! Now mine is trained, I am seeing 99%+ accuracy (in fact, for the past 24 hours, I've seen 100% accuracy!)