Thunderbird to support Microsoft Exchange protocol natively in July 2024, using Rust

Thunderbird, the popular open source email client, is set to natively support the Microsoft Exchange protocol with its next Extended Support Release (ESR) in July 2024. Until now, this functionality was only accessible via an add-on, despite being a highly-requested feature among Thunderbird users.

The initial roll-out of the Exchange support will only cover email due to the magnitude of the project. Support for calendar and address book features are slated to follow at a later date.

For the implementation of this new protocol support, the Thunderbird team has selected the Rust programming language. The choice was based on Rust's performance, memory safety, modularity, and ecosystem. This will be the first instance of Thunderbird incorporating code written in Rust.

The forthcoming Thunderbird version is expected to support Microsoft’s Exchange Web Services (EWS). It should also enable syncing of the account’s folder hierarchy from the remote server and display those folders within the Thunderbird user interface. This is just the beginning of this implementation, but more improvements should also follow as the Thunderbird team makes progress.