Babastik's AntiSpam Personal 1.0.4.5
The no nonsense, no compromise solution to stopping unsolicited email from cluttering your inbox. For Microsoft® Windows 98/Me/NT/2000 and XP. AntiSpam Personal uses what is called a White-list with Challenge and Response validation to stop emails from forged or invalid email addresses from reaching your inbox. It works with all email programs that access standard POP3 email servers: Outlook, Outlook Express, Eudora, etc.

0Spam.com Express 1.0
0Spam.com Express is the all-in-one, next generation anti-spam tool that protects you from the next generation of spams. Compatible with all versions of Windows and most E-mail clients, 0Spam.com Express can safely and efficiently remove spam from your existing POP3, Yahoo, Hotmail, GMail, or IMAP accounts. Integrates easily with your E-mail client and logs all scanned messages allowing you to see which messages were blocked and why.

PlexMailer 6.5
PlexMailer is an anti-spam software. It supports POP3, IMAP, LDAP, NNTP and MBOX protocols. It comes with dozens of filters such as Bayesian Filter and ORBS, MAPS and DUL. Also, it supports server side options and integration with other products.

SpamAI Anti-Spam Filter Software DR-4.20.0
SpamAI fights spammers with 100% spam rejection. Only email you approve or build rules for is allowed in. You preview unapproved email in a text-only holding tank that immunizes you from all malware. By simple point and click, including a convenient identity verification checkbox, you build rules for what you want to receive automatically.