Get Involved

Code

Code is located on Mozilla’s Mercurial server.

comm-central is the main Thunderbird repository.
Thunderbird also relies on the code from mozilla-central. See the build instructions for how to obtain all the code needed to build.
You can search the code on SearchFox.

There is also some code hosted on GitHub.

Thundernest contains the code for Thunderbird.net (this site), as well as the Thunderbird web server setup scripts.
Thunderbird on GitHub contains several Thunderbird related repositories.

Bugs

All Thunderbird bugs live on Mozilla’s Bugzilla. Bugzilla is a powerful tool and can be intimidating if you are not used to it. So check out these pre-defined searches to test the waters:

You can help out by triaging incoming bugs. Known bugs should be marked as duplicates, unconfirmed bugs often needs someone to see if they too can reproduce.
"Good first bugs" which are extra easy to try and fix when you are just starting out.
Mentored Bugs have a mentor who commits to helping you every step of the way.
Thunderbird bug queries is a wiki page with lots of useful searches.

Mailing Lists

tb-planning (Google Group Mirror) - For high level topics.
Maildev - A moderated mailing list for Thunderbird Engineering plans.
tb-support-crew - For those who help the users.
thunderbird-testers - For anyone who is helping test.
dev-apps-thunderbird (Newsgroup) (Google Group Mirror) - For technical and code related discussions, such as add-ons.
tb-enterprise - For ADMINISTRATORS to discuss large scale deployment and configuration of Thunderbird.
Add-on Developers List - For general discussions about creating add-ons, and is for add-on developers who need support in creating their add-ons.
Thunderbird UX List - Mailing list for discussion on UX in Thunderbird.
Thunderbird E2EE List - End-to-end Encryption using OpenPGP, OTR, and S/MIME.

Get Involved

Thunderbird is an open source project, which means anyone can contribute ideas, designs, code, and time helping fellow users.

Join Us

Make a Donation • Get Support • Report a Bug

Thunderbird

Thunderbird is a free email application that’s easy to set up and customize - and it’s loaded with great features!

The Future of Thunderbird

Experience cutting edge features. Provide feedback to help refine and polish what will be in the final release.

Thunderbird Nightly

Help us test the newest developments made to Thunderbird every day by using the unstable Nightly channel.

WARNING! Nightly is an unstable testing and development platform, make sure you back up important data regularly!