What are some alternatives?
When comparing Mailwasher and Spamfence.net, 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.
Scrollout F1 - Scrollout is a free and easy to use anti-spam email gateway designed for Linux & Windows administrators without advanced email security experience.
SpamSieve - Save time by adding powerful spam filtering to the e-mail client on your Mac.
SpamAssassin - Use this program to "Unspam" your mailbox(es).
POPFile - POPFile classifies email into categories you define.