Compare software

Exim vs Postal: catalog facts
Exim	Postal
Free Free and open source under the GNU General Public Licence.	Free Free and open source to run on your own server.
Linux, Self-hosted, Command line	Self-hosted
Very flexible mail routing Extensive checks for incoming mail	Self-hosted alternative to hosted transactional email services Handles both sending and receiving mail
Configuration is complex and differs from Sendmail A mail server, not a client for reading email	Requires running and maintaining your own mail server Deliverability depends on your own server reputation and setup
Downloadable app, Self-hosted	Self-hosted
Open source	Open source
License: GPL	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 September 24, 2026	Official website Full listing and sources Checked October 2, 2026

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