JMAP support in Spring 2026?

sunbeam60 · June 11, 2026, 4:57am

According to the launch video Spring 2026 includes JMAP support in the mail client.

But the Nextcloud Hub 26 Spring: Built together, designed for the future - News - Nextcloud community post doesn’t mention JMAP and I can only find IMAP support when I attempt to add a new email account.

And if you look at the source code for Nextcloud’s mail client, there’s not a single mention of JMAP in the mainline:

Is JMAP support actually out?

neufeind · July 8, 2026, 2:31pm

Still under development. Issue for JMAP is here:

github.com/nextcloud/mail

Support JMAP Protocol as Alternative to IMAP

offen 10:38AM - 17 Apr 20 UTC

BuZZ-dEE

enhancement 2. developing

## Feature Request As a user with a JMAP-enabled mail account (Fastmail, Stalwa…rt, etc.), I want to use Nextcloud Mail to access my email via JMAP. Currently, only IMAP is supported. ## Implementation JMAP (RFC 8620/8621) support is implemented by: - Introducing a protocol abstraction layer that allows the service layer to work with both IMAP and JMAP - Creating JMAP-specific client, mappers, and sync logic under `lib/JMAP/` namespace - Reusing domain models and service layer abstractions across both protocols - Adding protocol selection to the account setup UI Key library: [SebastianKrupinski/jmap-client-php](https://github.com/SebastianKrupinski/jmap-client-php) References: - RFC 8620: The JSON Meta Application Protocol (JMAP) - Mail - RFC 8621: The JSON Meta Application Protocol (JMAP) - Calendars - https://jmap.io/ ## Scope ### MVP (Phase 1) - Protocol selection (IMAP / JMAP) in account setup - Connect to JMAP servers with username/password - Sync mailbox structure from JMAP servers - Fetch messages with headers, flags, and IDs - Flag operations (read/unread, custom flags) - Move, copy, and delete messages - Send via SMTP (uses existing flow) - Use existing threading algorithm with JMAP message IDs - Integration tests against Stalwart JMAP server in CI - Existing IMAP accounts continue working ### Out of Scope - Auto-detection of JMAP server capability - OAuth2 authentication - Sieve filters - JMAP collaboration/sharing features ## Work Packages See linked sub-issues. ## Follow-ups - Auto-detect JMAP capability during account discovery - OAuth2 authentication for JMAP providers - Sieve filters for JMAP accounts - JMAP collaboration and sharing features ## Dependencies - SebastianKrupinski/jmap-client-php PHP library - Stalwart JMAP server docker container in CI ## Notes Implementation note: An AI agent was used in the planning phase of this feature.

sunbeam60 · July 9, 2026, 11:23am

Ok, makes sense. Strange to include it in the announcement video then.

jtr · July 11, 2026, 5:37pm

Not merged yet from what I can tell, but there is active work on it in progress as you can see if you click “Pull requests” in your screenshot.