1)   Outlook Express SPAM 100 v2.3.12
Outlook Express SPAM filter with artificial intelligence, Bayesian filtering technology, black lists and white lists and spam signitures. The built in artificial intelligence engine learns fast and work very well.

 2)   AntiSpam Sniper Pro 3.7
AntiSpam Sniper Pro is a security utility designed to protect your email from spam attacks, an effective buffer zone between your e-mail client and the Internet where every incoming e-mail is examined and those containing spam are filtered out

 3)   Antispam Software 1.5
Antispam software that lets you get back at spammers that choose to spam your e-mail. Better than a regular email anti spam filter (i.e., for outlook express, etc) because you can actually get back at the spammers. And better still, this is free anti

 4)   ~ 1 SpamItBack 1.042
Get spammers back, and send your own message telling them to stop spamming once, a thousand times, or as many times as you want back to them. And get a hi-score at the same time.