Anti-Spam SMTP Proxy
|Original author(s)||John Hanna|
|Developer(s)||Fritz Borgstedt in association with the ASSP community|
|Stable release||2.4.1(14085) / March 25, 2014|
|Type||Email spam filter|
|License||GNU General Public License|
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.
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)
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.
- Transparent SMTP proxy
- SpamAssassin, popular open source spam filtering that uses razor and other techniques to detect spam.
- Qpsmtpd, a similar project
- ASSP official homepage
- ASSP Wiki
- ASSP beta development site
- ASSP Deluxe for cPanel/WHM frontend for ASSP