ALL V2 versions with a build number less than 12130 have a bug which make SSL/TLS unavailable if the Perl module IO::Socket::SSL 1.70 is installed. Don't upgrade the module to version 1.70 or upgrade to the latest assp version.
- Multiple Weighted DNSBLs
- Multiple Weighted URIBLs
- Weighted Regular Expression Filtering
- Penalty Box
- Attachment Blocking
- ClamAV and FileScan
- Blocking Reporting
- LDAP support
- Backscatter Detection
- V2 - recipient replacement / GUI user access rights management
- V2 - MIME charset conversion / DKIM check and signing
- V2 - DB support for all hashes / level based open plugin support
- V2 - transparent proxy support / BATV check and signing
- V2 - Plugins: archive, full attachment check and replacement, OCR
- V2 - damping (steal spammers time)
- V2 - AUTH to relay host / POP3 collector
- V2 - configuration value and file synchronization
- V2 - Block Reports design could be customized
- V2 - Razor2 and DCC support via Plugin
- V2 - SNMP support (monitoring, configuring, controll-API)
- V2 - user group import (file or LDAP or command based)
- V2 - automatic crash analyzer Hidden Markov Model
- V2 - IPv6 socket support
- V2 - word stemming (several languages) for Bayesian analyzer
- V2 - Perl module autoupdate via PPM or CPAN
- V2 - Hidden Markov Model spam detection engine
- V2 - full unicode support
It has long been clear to me that the best place to stop spam is at an organization's SMTP server. This is true for the following reasons:
- Most spam has an invalid bounce address, so notifying non-delivery simply bounces to Postmaster, creating even more wasted bandwidth. Failing to notify non-delivery is a problem for false-positives. The SMTP server is the only place where spam can be stopped before entering your system.
- The only possible feedback for spammers to void an address is from the SMTP server.
- Spam that passes through your SMTP server into mailboxes incurs cost to your organization: storage, transmission, backup, deletion -- in all these ways spam costs you money. The only way to minimize cost is to reject it at the initial point.
Furthermore, one spam-stopping solution could work with all existing SMTP servers if it was implemented on a second level -- a transparent SMTP filtering proxy. This was my goal for this project.
I wanted a server that accepted connections on port 25, passing the transmission on to the official SMTP server, and relaying its replies back to the SMTP client. But when enough of the message had been transmitted to validate its legitimacy the ASSP server could either pipe the remainder of the message to the official SMTP server or close the connection to the official SMTP server and ignore the remainder of the message.
The Anti-Spam SMTP Proxy (ASSP) Server project is an open source platform-independent SMTP Proxy server which implements whitelists and Bayesian filtering to rid the planet of the blight of unsolicited email (UCE). UCE must be stopped at the SMTP server. Anti-spam tools must be adaptive to new spam and customized for each site's mail patterns. This free, easy-to-use tool works with any mail transport and achieves these goals requiring no operator intervention after the initial setup phase.
- Anti-Spam SMTP Proxy Server
- Anti-Spam SMTP Proxy Server | Free software downloads at SourceForge.net
- Stop spam with the Anti-Spam-SMTP-Proxy (ASSP)