JMAP for Calendars, Contacts and Files Now in Stalwart

I really hope Fastmail implements the JMAP spec for calendars and contacts soon. They’ve had the mail part of the spec implemented for a while, but it still requires CardDAV/CalDAV for contacts and calendar access.

We're working on it. We still use an unholy set of earlier versions of JMAP internally for our contacts and calendars; in particular the caldav_sync code is gnarly - I wrote it over 10 years ago when I knew less about calendars than I do now! It's still using an earlier branch of what became the perl Net::CalDAVTalk library interally, even though our frontend API is an almost-up-to-date version of what will become the JMAP Calendars spec eventually.

The downsides of developing and testing this stuff as we were writing it up!

We've finished rewriting the objectid generation to give smaller sized and more sortable IDs (they're an inverse of nanosecond internaldates now, plus some extra magic on the low bits for IMAP appends to avoid clashes)... which we wanted to speed up and reduce disk usage for the offline mode.

Next up is indeed updating to the latest spec on calendars and contacts. Files might take a bit longer, I really want to do some desktop clients for the files system, we have a really nice files backend at Fastmail which is only accessible via our interface or WebDAV right now.

Aside, this bit that Neil and the team are working on is something I think is the 'next big thing': https://www.ietf.org/archive/id/draft-ietf-jmap-emailpush-01...

The next, next big thing would be the Chatmail relays[1] supporting JMAP based servers (right now it's Dovecot) and this new targeted push extension for faster notifications without battery drain on mobile. I can see how the Fastmail mobile client will benefit from this RFC as well (it's already incredibly battery efficient, thanks to the team).

[1] https://github.com/chatmail/relay