What are some alternatives?
When comparing Spamfence.net and SpamBayes, you can also consider the following products
Mailwasher - Over 8 million people use MailWasher as their spam filter
Spamihilator - The free Anti-Spam-Filter Spamihilator removes more than 98% of spam mails before they even get into your inbox.
Spam Reader - Spam Reader is a free anti-spam add-on for Microsoft Outlook.
POPFile - POPFile classifies email into categories you define.
SpamSieve - Save time by adding powerful spam filtering to the e-mail client on your Mac.
BullGuard Spamfilter - Most people find spam e-mails the biggest nuisance on the Internet.