amavisd-milter is a sendmail milter (mail filter) for amavisd-new
2.4.3 or and sendmail 8.13 and above (limited support for sendmail
8.12 is provided) which use the new AM.PDP protocol.

Instead of older amavis-milter helper program, full amavisd-new
functionality is available, including adding spam and virus
information header fields, modifying Subject, adding address
extensions and removing certain recipients from delivery while
delivering the same message to the rest.

Homepage:
http://amavisd-milter.sourceforge.net/
