The Anti-Spam SMTP Proxy Server is a highly capable open-source platform-independent SMTP Proxy server that implements a wide range of advanced spam filters. These include auto-whitelists, self-learning Hidden-Markov-Model and/or Bayesian filters, Greylisting, DNSBL, DNSWL, URIBL, SPF, SRS, Backscatter prevention, Virus scanning, attachment blocking, Senderbase integration, and much more.

You can download the professional version 2.8.1 build 23131 from the 'Files' section, and there are also ready-to-run OVA versions available for Linux (Ubuntu 20.04 LTS) and FreeBSD 12.2.

Features

  • Multiple Weighted DNSBLs
  • Multiple Weighted URIBLs
  • Greylisting
  • Weighted Regular Expression Filtering
  • Bayesian
  • Penalty Box
  • SenderBase
  • SSL/TLS
  • SPF/SRS
  • Attachment Blocking
  • ClamAV and FileScan
  • Blocking Reporting
  • LDAP support
  • Backscatter Detection
  • recipient replacement / GUI user access rights management
  • MIME charset conversion / DKIM check and signing
  • multi DB support for all hashes / level based open plugin support
  • transparent TCP proxy support
  • Plugins: archive, full attachment check and replacement, OCR
  • damping (steal spammers time)
  • AUTH to relay host / POP3 collector
  • configuration value and file synchronization
  • Block Reports design could be customized
  • Razor2 and DCC support using Plugin
  • SNMP support (monitoring, configuring, controll-API)
  • user group import (file or LDAP or command based)
  • automatic crash analyzer Hidden Markov Model
  • IPv6 socket support
  • word stemming (several languages) for Bayesian analyzer
  • Perl module autoupdate via PPM or CPAN
  • Hidden Markov Model spam detection engine
  • full unicode support
  • DMARC support
  • privat Whitelist (legacy, domain based, user based)
  • privat IP and Domain lists (legacy, domain based, user based)
  • CPU affinity settings
  • web file commander
  • graphical statistic output (SVG)
  • native SSL support for target hosts
  • client SSL-certificate validation
  • privat SMIME signing
  • corporate SMIME signing, using a single privat certificate
  • content based executable attachment blocking
  • content based compressed attachment blocking
  • BATV check and signing
  • Message-ID signing and check FBMTV
  • remote support
  • Authenticated Received Chain (ARC) processing and signing
  • RSS feeds for blocked emails using Plugin
  • zero day virus detection
  • VirusTotal API

License

GNU General Public License version 2.0 (GPLv2)

Resources & Downloads

Anti-Spam SMTP Proxy Server
Download Anti-Spam SMTP Proxy Server for free. Anti-Spam SMTP Proxy Server implements multiple spam filters. The Anti-Spam SMTP Proxy (ASSP) Server project aims to create an open source platform-independent SMTP Proxy server which implements auto-whitelists, self learning Hidden-Markov-Model and/or Bayesian, Greylisting, DNSBL, DNSWL, URIBL, SPF, SRS, Backscatter, Virus scanning, attachment blocking, Senderbase and multiple other filter methods. Click ‘Files’ to download the professional version 2.8.1 build 23131.