Compare software

Cyrus IMAPSmarterMail
Free

Free and open source.

 Freemium

Can be downloaded for free, with paid licences available to buy.

Linux, Self-hosted Windows, Linux, Web, Self-hosted
  • Mail, calendars and contacts in one server
  • JMAP support alongside IMAP
  • Native MAPI support for Outlook without plug-ins
  • Calendars, contacts, tasks, chat and meetings included
  • Complex to configure compared with all-in-one servers
  • No bundled webmail
  • Proprietary, closed-source software
  • Running a mail server requires ongoing administration
Self-hosted Downloadable app, Self-hosted
Open source Closed source
License not stated License not stated
No account needed Not stated if an account is needed
Not stated if it works offline Not stated if it works offline

Checked September 24, 2026

Checked October 1, 2026

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