Compare software

Postal vs Haraka: catalog facts
Postal	Haraka
Free Free and open source to run on your own server.	Free Free open-source software.
Self-hosted	Linux, Self-hosted, Command line
Self-hosted alternative to hosted transactional email services Handles both sending and receiving mail	High performance SMTP handling Flexible plugin system in JavaScript
Requires running and maintaining your own mail server Deliverability depends on your own server reputation and setup	Handles SMTP only; needs other software for mailbox access Customisation requires JavaScript knowledge
Self-hosted	Downloadable app, Self-hosted
Open source	Open source
License not stated	License not stated
No account needed	No account needed
Not stated if it works offline	Not stated if it works offline
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked October 1, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.