SA Proxy (Spam Assassin Proxy) is based on the open source software, Spam Assassin. It runs as a local proxy server that sits between your email program and your POP3 mail account.

All you need to do is start SAProxy and configure your email program to connect to it instead of the normal incoming mail server (documentation shows how to do it). The next time you check your email, all spam messages will be tagged with ****SPAM**** in the subject line, allowing you to easily recognize them, or to create a rule in your email program that will move those tagged messages into a separate folder.

Spam Assassin uses Bayesian filtering which is highly accurate and can learn from new spam as it is detected. The program does not delete any spam, but only marks it, leaving it up to you what to do with it.