Wasn't JMAP initiated by Fastmail and initially mostly based on their internal implementation.

Initially, the proposition relied on Fastmail protocol, which was/is superior to IMAP. It was pleasing that standardization began, as MS Activesync charged a few dollars per user just for the protocol. Even the Apache James mail server supported it as a draft. Despite becoming a standard make it better , but lost momentum.

Still hope at least both will add push notification to 3th party apps. And a BIG hope for https://stalw.art/

+1 for Stalwart

> its not worth the effort to implement for pretty much anyone, so it’s only idealists like Fastmail who’ve done so anyway.

Worth mentioning that Fastmail use an open source backend: Cyrus[0] - which started adding JMAP support in 2015 (though I suspect that was Fastmail devs contributing the feature).

[0] http://www.cyrusimap.org/

Yeah, but the target of Proton’s efforts with Gluon is the clients, since Gluon is part of the ProtonMail Bridge software.

Their primary targets are Microsoft Outlook, Apple Mail and Thunderbird, none of which speak JMAP at present. So Proton has very little to gain from implementing JMAP, since only niche clients support it at this point.

Classic chicken and egg problem, unfortunately.