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.

I don’t think JMAP Calendar spec has been ratified yet.

https://datatracker.ietf.org/doc/draft-ietf-jmap-calendars/

And Contacts was only 10-months ago.

https://www.rfc-editor.org/rfc/rfc9610.html

What good is a protocol like JMAP as long as common clients like Thunderbird, K-9 Mail, the iPhone email client and others don't support it? Without some concerted effort it will never take off. Then there is the question of what problem it solves that isn't already solved by existing solutions.

Next time an iCal event invitation screws up the time zone, return to this question.

JMAP works in my email client, aerc.

The lack of support for JMAP in common mail clients has been my concern for years. And recently Fastmail went ahead with releasing its own Electron-based desktop app that uses JMAP for its mail service. Mozilla Thunderbird could do with some support (financial and/or people wise) to get JMAP implemented. I don’t know if Fastmail the company has done much on this aspect, but hope they do.

I think Thunderbird will implement JMAP at some point, because as I understand it their upcoming hosted mail service, Thunderbird Pro will offer it.

I looked into adding JMAP support to Thunderbird but the client is so tied around the ideas and principles of IMAP, it needs surgical refactoring of many parts of it and I don’t love C++.

So instead in my spare time I am developing a JMAP only gnome email client, using many Stalwart libraries. Think Geary but Rust instead of Vala, GTK4 instead of GTK3 and JMAP instead of IMAP. It’s been mostly an excuse to play with Rust and gtk-rs and Relm4 (beautiful Elm inspired rust bindings for GTK4). Someday, it will be released.

Client support for a new protocol is never that quick, but I believe adoption will happen, at least outside of the big providers, who will never support it.

iCal is timezone-aware, if something goes missing there, that's the fault of a broken implementation.

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.

Isn't their upcoming "Thundermail" service actually based on/using Stalwart?

Here is a quote I found on https://thunderbird.topicbox.com/groups/planning/T437cd854af...:

> We have been experimenting with this for a while now and are using Stalwart as the software stack we are building upon. We have been working with the Stalwart maintainer to improve its capabilities (for instance, we have pushed hard on calendar and contacts being a core piece of the stack).

However, unfortunately I am unsure whether this is a good source or official page.

Off-Topic: Thank you for not only providing a stellar service with Fastmail, but also for contributing back to the OSS ecosystem and the specifications/RFC work. This takes a lot of time and we all benefit from this work. It helps many people/small IT shops to run a system outside of the "big ones". Again, thank you.