mail-filter/MailScanner
Free Anti-Virus and Anti-Spam Filter
USE Flags
clamav
Global: Adds support for Clam AntiVirus software (usually with a plugin)
doc
Global: Adds extra documentation (API, Javadoc, etc)
exim
* This flag is undocumented *
postfix
Global: create user with permissions for proper postfix interaction
spamassassin
Global: Build mail-filter/spamassassin plugin