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.

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