Spamnix for Mac

From Spamnix Software:

Spamnix for Eudora is a plug-in for Qualcomm Eudora that blocks unwanted spam email. Once you install it, it automatically runs whenever Eudora runs. There are no separate programs to worry about or additional windows cluttering up your screen. Spamnix comes pre-configured to block almost all of the spam email you receive.

Spamnix checks for spam automatically each time you download mail. All spam is transfered to a special mailbox called "Spamnix" (with Eudora 6, it can instead be transferred to the "Junk" mailbox). At your leisure, you can then review the blocked spam and delete it all at once; this is much faster than having to deal with it every time you read new mail. Or, if you want, you can configure Spamnix simply to delete all spam immediately.

Since Spamnix's spam recognition is not based on specific email addresses, you can get started without configuring it in any way. But no spam-recognition system is perfect, and Spamnix will make mistakes. It will virtually never mistakenly block a personal message from any individual to you. It will inevitably let through some spam that it does not recognize. Also, some highly commercial-looking messages (such as promotions or newsletters from companies you have legitimately signed up for) might be blocked. In this case, you can use Spamnix's Accept/Reject feature to create a rule to recognize such messages in the future.

Spamnix also uses Bayesian filtering, a statistical machine-learning technique that analyzes the words in sample training spam and non-spam messages and uses that information to identify which category new messages belong in. Spamnix's Bayesian system can be trained either on individual messages or entire mailboxes at a time. Once trained, Spamnix becomes even more accurate at detecting what you consider spam.