As of 0.96 Sendmail::PMilter is being hosted on CPAN. Please use CPAN to obtain it as everything still on SourceForge is outdated.
Sendmail::PMilter on CPAN
PMilter is an attempt to reimplement Sendmail's milter (mail filter) protocol in pure Perl. There are many reasons for this, including independence from Sendmail's libmilter, as well as freedom from POSIX threads (helps stability for Perl filters), etc.
In addition, PMilter provides a milter protocol specification document (see below), and a package of flexible, extensible milter tools and prefabricated modules via the Mail::Milter package.
PMilter is beta software. Don't expect it to be "production" quality, nor to have extensive documentation, though it does essentially work at the core level at this point.
Prior to the 0.90 release, this project was hosted on duh.org. From 0.90 to 0.95 it was hosted at SourceForge. It is now hosted at CPAN.
Sendmail::PMilter author: Todd Vierling - email@example.com
Current maintainer: AVAR on CPAN