The only thing I know about IMAP are from JMAP, so I cannot say what is lacking in IMAP per se. As far as I know a couple things that are pain points for me wh

The only thing I know about IMAP are from JMAP, so I cannot say what is lacking in IMAP per se. As far as I know a couple things that are pain points for me when using thunderbird/other IMAP clients (weird search limitations, strict folder hierarchy organization) are due to how IMAP was designed, but these are mostly minor issues that I imagine would not require a new protocol. What I hope the advantage of JMAP will be is that it will provide a more flexible foundation for gmail-like interfaces on an open protocol. At least all IMAP clients I have used have always felt... clunky and counter intuitive (I started using email with gmail, so maybe I just never learned the skills) even if IMAP already had all the good things JMAP claim, I think that the different focus on message and less historical baggage have a good change of producing designs that will feel more natural to me.