Best Free Spam Filter for Experienced Users

There are many spam filters available employing lots of different techniques. In my experience "learning" spam filters that use the Bayesian statistical approach out-perform most other types of filters. Not only are they better at detecting spam, they are also less liable to classify your real mail as spam. This effectiveness takes a little time to develop as the filter has to be trained to recognize your spam from your normal mail. It takes a week or so before results start becoming accurate and best results may take a month or more.

POPFile was one of the first Bayesian filters and is still one of the best. It works as a proxy mail server so that means that it can be used with any POP email client. Setup is reasonably straightforward for experienced users but beginners may be better of with Mailwasher.

Spamato is a promising, free open source spam filter with a difference. Rather than rely on one Bayesian spam filter to classify spam, Spamato uses a “multifaceted spam filter system that combines a variety of anti-spam techniques”. Like POPFile, it can work with any email client but additional plugins are available to integrate Spamato into Outlook, Thunderbird and the Mozilla Mail Client.

Other excellent free Bayesian spam filters available include SpamBayes and K9. Both are simple to install though, like all statistical filters, they need to go through a training phase before they reach full effectiveness. A newer addition to this list is Spam Terrier from Agnitum. If you are new to Bayesian spam filters and use Outlook, you will find this program is a tad easier to install and use than SpamBayes or K9.

K9
Website: http://www.keir.net/k9.html
Author: Robin Keir
Version: 1.2.8
Date: April 18, 2004
Download File size: 113 KB
License: Freeware
Operating systems supported: Windows 95, 98, Me, NT, 2000, XP
64 Bit Capable: No
Other languages supported: Dutch, English, French
Additional Software Required: No
Other relevant information: Supports the following protocols: POP3

This software category is maintained by volunteer editor Denis S