Clam AntiVirus is an anti-virus toolkit for Unix. The main purpose of this software is the integration with mail servers (attachment scanning). The package provides a flexible and scalable multi-threaded daemon, a commandline scanner, and a tool for automatic updating via Internet. By itself, ClamAV will only scan your hard drive. It won't scan e-mails. For a complete antivirus mail scanning package, we use MailScanner in conjunction with ClamAV.

MailScanner scans all e-mail for viruses, spam and attacks against security vulnerabilities. It currently protects over 5 billion e-mails every week.* MailScanner has been developed in a world-leading Electronics and Computer Science Department at the University of Southampton.

* As of November 2005

Apache SpamAssassin is the #1 open source spam filter on the web. It uses a variety of mechanisms including header and text analysis, Bayesian filtering, DNS blocklists, and collaborative filtering databases. SpamAssassin runs on a server, and filters spam before it reaches your mailbox.

SpamAssassin's practical multi-technique approach, modularity, and extensibility continue to give it an advantage over other anti-spam systems. Due to these advantages, SpamAssassin is widely used in all aspects of e-mail management. You can readily find SpamAssassin in use in both e-mail clients and servers, on many different operating systems, filtering incoming as well as outgoing e-mail, and implementing a very broad range of policy actions. These installations include service providers, businesses, not-for-profit and educational organizations, and end-user systems. SpamAssassin also forms the basis for numerous commercial anti-spam products available on the market today.