Anti-Spam SMTP Proxy Server, Free and Open-source Projects
Anti-Spam SMTP Proxy Server implements multiple spam filters
The Anti-Spam SMTP Proxy (ASSP) Server project provides an open-source, platform-independent SMTP Proxy server designed to enhance email security by implementing a variety of filtering techniques.
Key features include auto-whitelists, self-learning Hidden-Markov-Model and Bayesian filters, Greylisting, DNSBL, DNSWL, URIBL, SPF, SRS, Backscatter protection, virus scanning, attachment blocking, and Senderbase integration.
The project offers a professional version (V2.8.1 build 23131) and ready-to-run OVA files for Linux (Ubuntu 20.04 LTS) and FreeBSD 12.2. Development on V1 has ceased since 2014, with only potential bug fixes in the future.
Users are encouraged to upgrade to V2, which continues to receive active maintenance.
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
Systems
- Windows
- Linux
- macOS
License
GNU General Public License version 2.0 (GPLv2)
Resources & Downloads
venkat6677
