[brongondwana]

The big benefit with JMAP is the state strings and /changes operation which allows even in the face of failures to recovery quite cleanly. It's really more a data synchronising protocol (RFC8620) with email support on top (RFC8621) and the new protocols coming in.

[hyhconito]

Section 3.10 of RFC8620 scares me. I know a lot about that and a lot of the complexity around that trite point is missing.

Note I've designed and built a complex messaging system that runs over HTTP over unreliable connections and run it in production for 15 years so I know what can and does go wrong.

Popcorn at the ready.

[Semaphor]

It’s not as if Fastmail haven’t run JMAP in production at a pretty big level for quite some time by now.

[hyhconito]

And I dumped them because their client was buggy, doesn’t work offline on mobile devices and I had to use IMAP anyway…

[spondyl]

> doesn’t work offline on mobile devices

To some degree, that isn't true anymore as of last week but of course, you meant when you used it, not generally: https://www.fastmail.com/blog/offline-in-beta/

[hyhconito]

Oh so some of it works offline.

Useless to me. Seriously.

I write a lot of email on planes and do a lot of email management.

All that works on the default Apple stuff as shipped other than account management. Using IMAP and iCal etc.

[NoahKAndrews]

Have you looked at their list of what doesn't work offline? It seems like it's mainly attachment management limitations than limitations of managing the emails themselves.