Chainmail is a Sendmail® mail filter (milter), which allows to manipulate emails passing through a Sendmail® mail server in various ways. Based on the content of the email header and bodies, chainmail can add or remove recipients, reject messages, etc. Chainmail is intended to be a general purpose mail filter, comparable to the well-known procmail program in its mail filter mode.

Chainmail is copyright © 2003-2004 by Leonid Zeitlin (<lz@europe.com>). Chainmail is distributed under the terms of GNU General Public License version 2.0.