Compare software

Haraka vs Exim: catalog facts
Haraka	Exim
Free Free open-source software.	Free Free and open source under the GNU General Public Licence.
Linux, Self-hosted, Command line	Linux, Self-hosted, Command line
High performance SMTP handling Flexible plugin system in JavaScript	Very flexible mail routing Extensive checks for incoming mail
Handles SMTP only; needs other software for mailbox access Customisation requires JavaScript knowledge	Configuration is complex and differs from Sendmail A mail server, not a client for reading email
Downloadable app, Self-hosted	Downloadable app, Self-hosted
Open source	Open source
License not stated	License: GPL
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 1, 2026	Official website Full listing and sources Checked September 24, 2026

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