Best self-hosted communication - email - mail transfer agents
[Mail Transfer Agents](https://en.wikipedia.org/wiki/Message_transfer_agent) (MTAs) - [SMTP](https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol) servers.
We track 9 self-hosted communication - email - mail transfer agents projects. The median health score in this category is 32, against 0 projects rated healthy or better and 2 showing little recent activity. The table below is ordered by health score, not popularity — the most starred project in a category is frequently not the best maintained one.
| # | Project | Health | Activity | Stars | Built with | Last release |
|---|---|---|---|---|---|---|
| 1 | Haraka Fast, highly extensible, and event driven SMTP server. | Steady · 57 | 5.6k | Nodejs | 5 Sept 2026 | |
| 2 | OpenSMTPD Secure SMTP server implementation from the OpenBSD project. | At risk · 32 | 586 | C, deb | 13 Sept 2026 | |
| 3 | DragonFly A small MTA for home and office use. Works on Linux and FreeBSD. | At risk · 20 | 265 | C | — | |
| 4 | chasquid SMTP (email) server with a focus on simplicity, security, and ease of operation. | Unrated | — | Go | — | |
| 5 | Courier MTA Fast, scalable, enterprise mail/groupware server providing ESMTP, IMAP, POP3, webmail, mailing list, basic web-based cal | Unrated | — | C, deb | — | |
| 6 | EmailRelay A small and easy to configure SMTP and POP3 server for Windows and Linux. | Unrated | — | C++ | — | |
| 7 | Exim Message transfer agent (MTA) developed at the University of Cambridge. | Unrated | — | C, deb | — | |
| 8 | Postfix Fast, easy to administer, and secure Sendmail replacement. | Unrated | — | C, deb | — | |
| 9 | Sendmail Message transfer agent (MTA). | Unrated | — | C, deb | — |
Which one should you run?
If you want the safest bet on longevity, Haraka is the best-maintained project in this category right now at 57/100. OpenSMTPD is the closest runner-up (32/100) — see the side-by-side comparison.
A health score measures whether a project is alive and shipping. It does not measure whether it has the feature you need. Use it to rule options out, then compare on features.