Planned work for the 2024 release of Thunderbird.
Below are the large projects planned for the 2024 release of Thunderbird.

Primary Objectives

This is a list of all the primary objectives and efforts that we will try to complete for 2024. These are not currently tied to any particular beta release nor ESR release and they will be available when ready.

Mozilla Account + Sync

Implement Mozilla Account login and syncing server functionalities to synchronize accounts and settings across installations.

Exchange email support

Implement full support for Microsoft Exchange (EWS) into core for account create and email usage.

Global Message Database

Move away from the old Mork database and implement a real global message database, enabling conversation view and other modern paradigms.

Telemetry Heat Mapping

Automatic generation of a visual heatmaps from telemetry clicks.

Cards View UI completion

Finalize the cards view interface to implement all missing features and flexibility required.

Message list context menu

Improve the context menu of the message list to make it more usable and digestible.

Dark reader email content

Support full dark mode also for message content and properly handle images and graphics.

Folder Pane UI completion

Complete the work of the new folder pane that was starting with the Supernova effort.

Account Hub

Implement a single entry point for all account setups and offer a better guided setup experience for first time users.

Firefox Translate

Opt in feature allowing users to translate email content.


Standalone Rust component experiment of a notes implementation in Thunderbird.

Maintenance Sprints

Alongside the primary objective for the year we will continue the effort of improving our codebase, keeping up with the changes upstream, as well as bug fixes and performance improvements.
Some of the efforts of this maintenance cycle are:
  • OpenPGP and S/MIME improvements and fixes
  • Add-ons API Improvements
  • Fluent Migration
  • ESMification

Out of scope

As we focus on these primary objectives with the goal of bringing them to full completion, as well as making sure we have enough resources to tackle bug reports and regressions, we won't be dedicating any major commitment to the following areas of the application during this year.
  • Calendar
  • Chat
  • Tasks
  • Settings
  • Compose
  • Search
  • and everything else...
We will always have dedicated resources allocated to tackle crashes or performance regressions caused by any of these components.