A milter that performs DKIM and ARC signatures.

Extensible nativ sendmail mail filter implementation for java

Block connections from remote sites that are sending spam, thus reducing load on your mail server.

smf-spamd: Smart Sendmail Filters

DKIM signing for the mailserver project

milter manager is a free software to protect you from spam mails and virus mails effectively with milter.

A mail filter to block emails from countries from which you don't wish to receive e-mails

Docker image for Amavis in mailserver

It's a lightweight, fast and reliable Sendmail milter that implements the Sender Policy Framework

Stop Spam

Library of supporting functions, APIs, and tools for SnertSoft BarricadeMX and milters.

Nager.MtaMilter is a C# Milter implementation for seamless mail server integration (Postfix, Sendgrid, Stalwart).

signing-milter enables you to s/mime sign an ordinary mail while passing a MTA. Base on https://signing-milter.org/ by Andreas Schulze

Extracts URLs from a mail message and checks it against one or more URI blacklists.

Exchange Online Tenant Authorisation Milter (Mail-Filter)

Provide an interface to the popular open source Clam Anti-Virus scanner.

An independent implementation of the RFC 4408 Sender Policy Framework (SPF-Classic).

Reject mail according to different message size limits per IP, domain name, or sender address.

An interface to the popular open source SpamAssasssin mail analysis tool, which returns a score based on a comprehensive set of patterns and Bayesian checks.

Grey listing is an anti-spam technique that keeps track of tuples consisting of the connecting IP, sender's envelope, and recipient's envelope. If a tuple, does not exist in the cache, then a new entry is added and kept until it expires and the message is temporarily rejected.