SpamAssassin : Security Add-on

             SpamAssassin provides efficient scoring spam filters, support for SPF sender authentication and Bayesian filtering. While SpamAssassin catches most spam out of the box, the threshold possibly has to be adjusted to eliminate false positives.

Advantages:

•     SpamAssassin has a high spam detection rate

•     Uses sophisticated scoring filters, Bayesian statistics, blacklists and SPF for authentication

•     SpamAssassin works seamlessly in just about every environment

Disadvantages:

•     Default SpamAssassin setup is a tad too aggressive

•     Ongoing training of SpamAssassin's Bayesian filtering is a bit cumbersome

Description:

•     SpamAssassin is a mail filter using a number of scoring heuristics to identify spam.

•     Employs header and mail body analysis as well as blacklists and collaborative spam databases.

•     Marks spam for later filtering (via procmail, the mail transfer agent, an email client,...).

•     SpamAssassin gives a detailed report of its scoring process for every identified spam message.

•     Defangs HTML messages to eliminate the risk of spammers exploiting your privacy with remote images.

•     Further advanced HTML parsing helps detect hidden text and other obfuscation tricks.

•     SpamAssassin can report detected spam automatically to community spam databases like Vipul's Razor.

•     When trained, SpamAssassin makes great use of Bayesian statistics to classify mail, too.

•     SpamAssassin supports SPF and DomainKeys sender authentication as well as Hashcash.