Anti-Spam SMTP Proxy

The Anti-Spam SMTP Proxy (ASSP) server project is an Open Source, Perl based, platform-independent transparent SMTP proxy server available at SourceForge.net that leverages numerous methodologies and technologies to both rigidly and adaptively identify e-mail spam. ASSP is easy to set up because it requires only minor changes to the configuration of your Mail Transfer Agent.

Features

Some ASSP's features are:

• Bayesian analysis
• Penalty Box (PB) trapping
• DNSBL/RBL (Realtime Blackhole Listing)
• URIBL (Uniform Resource Identifier Black Listing)
• Multi-level SPF (Sender Policy Framework) validation and blocking
• SRS (Sender Rewriting Scheme) fix-up
• Session Delaying/Greylisting and connection response delaying
• Sender validation and recipient validation
• Multi-level attachment blocking (based on block lists or allow lists)
• As well as multiple RFC validation mechanisms.
• Multi-threaded (Since version 2.x)
• Platform independent (Written in Perl)

Disadvantages

From a technical point of view, the software is written in an obfuscated style which makes it difficult to debug, and update. For example, the entire program is written as a single Perl program file, rather than being broken into modules.

See also

• Transparent SMTP proxy
• SpamAssassin, popular open source spam filtering that uses razor and other techniques to detect spam.
• Qpsmtpd, a similar project

External links

• ASSP official homepage
• Forum
• ASSP Wiki
• ASSP beta development site
• ASSP Deluxe for cPanel/WHM frontend for ASSP