IMAP, JMAP and the future of open email standards - Bron Gondwana [FOSDEM 2019]

Currently, e-mail clients is almost completely IMPA4 + extensions. There are proprietary protocols used by Microsoft and GMail. JMAP is a modern non-proprietary alternative.

JMAP is evolved from FastMail’s own proprietary protocol, which they opened. But unless it’s an IETF RFC, nobody is interested.

Standars are constraints. They are solid, a great basis for a test suite. But becuase they are fixed, they take a lot longer to write than the software itself. IETF is a great breeding ground: that exposure and discussion has made the JMAP standard both simpler and more powerful than the FastMail protocol was.

In addition to JMAP, there is also a standardized extension of IMAP in the work: EXTRA. It’s a collection of unpublished extensions and idea.

See who is using it.

Cyrus IMAP server already has JMAP support. offers a free e-mail service.