There is lots of free anti-virus stuff for Linux email servers. http://freshmeat.net/projects/amavis/ http://www.amavis.org/ http://www.sng.ecs.soton.ac.uk/mailscanner/ How To Install Postfix, Amavis, ClamAV, and Spamassassin on Debian Linux: http://www.fatofthelan.com/articles/articles.php?pid=22 Using MailScanner/Postfix/SpamAssassin/ClamAV in Gentoo Linux: http://wiki.linuxquestions.org/wiki/Using_MailScanner/Postfix/SpamAssassin/ClamAV_in_Gentoo_Linux Linux Journal: Paranoid Penguin - Adding Clam Antivirus to Your Postfix Server http://www.linuxjournal.com/article/7778