The Ada Milter API is a binding to Libmilter, the Sendmail mail filtering API. A milter is a daemon that assists a Mail Transfer Agent, such as Sendmail or Postfix, in checking messages and deciding whether to accept, reject or modify them. This binding lets you write milters in Ada.
The source is available as releases and in a public Git repository. It requires the System_Log package.
Version 2.1.1 of the Milter API is intended to match version 1.0.1 of Libmilter, and provides all of the features in that version of Libmilter. This version of the Milter API has been used successfully with Postfix 2.7.1.
Version 1.2.1 is intended to match the version of Libmilter that comes with Sendmail 8.13.8, where the value of SMFI_VERSION is 2. It provides almost all of the features in that version of Libmilter, but lacks features introduced in later versions. This version of the Milter API has been used successfully with Postfix 2.3.8.
There is documentation in the form of comments in the package specification. In addition to those you should probably read the Libmilter documentation, which is available at Milter.org and is also included with Sendmail.
Starting in version 2.1.1 there are build and installation instructions in the file INSTALL in the source package.
The Ada Milter API is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License version 3, as published by the Free Software Foundation.