MailScanner is a virus & spam email scanner, that (in its' most common configuration) sits on your MTA and checks all mail that runs through it.
MailScanner's website can be found 
here. Look at MailScannerNotes for other info.
Debian Woody Backport of Mailscanner: http://www.wlug.org.nz/archive/debian/. (That will eventually become an APT repository...)
7 pages link to MailScanner:
