What are some alternatives?
When comparing Mailwasher and SpamBayes, you can also consider the following products
Spam Reader - Spam Reader is a free anti-spam add-on for Microsoft Outlook.
Spamihilator - The free Anti-Spam-Filter Spamihilator removes more than 98% of spam mails before they even get into your inbox.
POPFile - POPFile classifies email into categories you define.
Scrollout F1 - Scrollout is a free and easy to use anti-spam email gateway designed for Linux & Windows administrators without advanced email security experience.
Spamfence.net - Professional e-mail security free for private use: With Spamfence.
SpamAssassin - Use this program to "Unspam" your mailbox(es).