Haraka
Fast, highly extensible, and event driven SMTP server.
Maintained, but at a slower pace than the leaders in its category.
Commit activity more than 25% of tracked projects; popularity more than 69%. How this is calculated.
Commits, last 11 months
| Stars | 5.6k |
|---|---|
| Latest release | v3.3.4 · 5 Sept 2026 |
| Repo updated | 5 Sept 2026 |
| Licence | MIT |
| Built with | Nodejs |
Is Haraka actively maintained?
Development is ongoing. The repository recorded 79 commits over the same window, and the last three months alone account for 23 of them.
The most recent tagged release, v3.3.4, shipped within the last month — a current, installable version exists today.
Among the 9 communication - email - mail transfer agents projects we track, Haraka currently has the highest health score.
What Haraka actually does
Haraka is an asynchronous mail transfer agent built to process incoming and outgoing email at high volume. Written in JavaScript, it uses an event-driven architecture to handle network traffic efficiently without spawning heavy worker processes for every connection.
Best fit: It is suited for administrators looking to build custom email routing logic or security filters using JavaScript plugins rather than traditional configuration languages.
Worth knowing: Node-based mail servers demand careful monitoring of event loop blockages and memory limits under sustained high traffic loads, and they have a smaller community footprint than established alternatives like Postfix or Exim.
Deployment notes
Because it runs on Node.js, you will need a modern runtime environment installed on your server along with process managers like PM2 to keep the service running reliably in the background.
Links
Haraka as a replacement for
Alternatives to Haraka
Projects in the same categories, ordered by health score.
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Message transfer agent (MTA) developed at the University of Cambridge.