Anti-Spam SMTP Proxy

Anti-Spam SMTP Proxy
Original author(s)	John Hanna
Developer(s)	Thomas Eckardt in association with the ASSP community
Stable release	2.8.1(23131) / May 11, 2023;2 years ago (2023-05-11)
Preview release	2.8.2(23136) / May 16, 2023;2 years ago (2023-05-16)
Written in	Perl
Operating system	Cross-platform
Type	Email spam filter
License	GNU General Public License
Website	assp.sourceforge.net

The Anti-Spam SMTP Proxy (ASSP) is an open-source, Perl based, platform-independent transparent SMTP proxy server.

Features

Some ASSP's features are:

• Hidden Markov Model spam filtering
• Bayesian spam filtering
• whitelisting
• Penalty Box (PB) trapping
• DNSBL/RBL (Realtime Blackhole Listing)
• URIBL (Uniform Resource Identifier Black Listing)
• Multi-level SPF (Sender Policy Framework) validation and blocking
• DKIM signing and validation
• DMARC validation and reporting
• 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 or content based executable blocking)
• As well as multiple RFC validation mechanisms.
• Multi-threaded (Since version 2.x)
• Platform independent (Written in Perl)

See also

• Free and open-source software portal

• 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
• ASSP sourceforge project page
• Forum
• ASSP Wiki
• ASSP beta development site
• ASSP Deluxe for cPanel/WHM frontend for ASSP