The Anti-Spam SMTP Proxy (ASSP) Server project aims to create an open source platform independent SMTP Proxy server which implements whitelists, Bayesian, and virus filtering to help stop unsolicited commercial email (UCE). Anti-spam tools should be adaptive to new spam and customized for each site’s email patterns. This easy to use tool works with any mail transport and achieves these goals requiring no operator intervention after the initial setup phase.
BackupMX consists of two programs, 'Store' and 'Forward'. Store accepts SMTP connections, takes all mail given to it, and stores it in a file. Forward takes that file and forwards it over SMTP to a fixed destination. This is code for integrating into your own projects rather than using as is. It is suitable for creating a disaster-recovery mail handler, but would also make a good basis for a spam filter, a tarpit, a honeypot, or a greylist filter. It is written in simple C, and has no external dependencies such as libsmtp.
COMDOM Antispam is a high-capacity platform designed for the requirements of ISPs and other large organizations that must fight spam. COMDOM is a powerful anti-spam system operating as a stand alone mail gateway with relay control, authentication, and load balancing support. The system consequently can be used together with mail servers or as a stand alone gateway for several mail servers. The robustness, flexibility, and the high data throughput capacity of COMDOM Antispam allow for the software to be deployed for a range of solutions.
GNU Anubis is an SMTP message submission daemon. It represents an intermediate layer between the mail user agent (MUA) and mail transport agent (MTA), receiving messages from the MUA, applying to them a set of predefined changes, and finally inserting modified messages into an MTA routing network. The set of changes applied to a message is configurable on a system-wide and per-user basis. The built-in configuration language used for defining sets of changes allows for considerable flexibility and is easily extensible.
The Gordano Messaging Suite (GMS) is a highly flexible and reliable suite of messaging products. Customers can choose which components meet their needs from email, Webmail, collaboration, instant messaging, calendaring, SMS, and list server software all of which can be complimented by high level anti-spam, anti-virus, and archiving options.
JSpamfilter is software that intercepts connections from remote Internet mail servers before they can connect to your mail server. The originating IP address for the inbound connection is then checked against one of the DNS-based SPAM Blackhole (DNSBL) lists maintained on the Internet by various organizations. If the check passes, the connection is allowed to proceed to your mail server; if it fails, the connection is told that the mail server is unavailable, then dropped.
MailStripper Pro is a mail scanner that aims to remove spam and viruses from incoming mail. It recognises and decodes many obfuscation techniques used by spammers and uses several different mechanisms to recognise spam which are immune to Bayes poisoning, and has achieved real-world success of over 99.8%. It is MTA-independent and does not implant itself into your mail server. Instead, it functions as a proxy, allowing the MTA to reside on a different server.