Top 3 C Mail Transfer Agent Projects

Exim

9 699 9.2 C

Exim Mail Transport Agent - source, testsuite and documentation

Project mention: Is it right to blame Google/Yahoo for deprecating an email forwarding service? | news.ycombinator.com | 2024-01-14

Documentation for ARC is pretty sparse.
The instructions for setting it up in Exim (default MTA on Debian systems) can be found here: https://github.com/Exim/exim/blob/master/doc/doc-txt/experim...
(AFAICT, there is absolutely no mention of ARC in the main Exim documentation: https://exim.org/docs.html)

OpenSMTPD

18 475 9.1 C

This is official OpenSMTPD Portable repository. Forks, pull requests and other contributions are welcome!

Project mention: OpenBSD acme-client で Let's Encrypt 証明書を取得する | dev.to | 2023-09-09

WorkOS

workos.com sponsored

The modern identity platform for B2B SaaS. The APIs are flexible and easy-to-use, supporting authentication, user identity, and complex enterprise features like SSO and SCIM provisioning.
Courier MTA

5 70 7.1 C

Courier Mail Server

NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020).