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We’re Hiring a Developer to Work on Thunderbird Full-Time!

11 responses

The Thunderbird Project is hiring for a software engineer! We’re looking for an amazing developer to come on board to help make Thunderbird the best Email client on the planet! If you are interested you can apply via the link below, following the job description.

Here’s the job description:

Title: Thunderbird Software Engineer

About Thunderbird
Thunderbird is a email client depended on daily by 25 million people on
three platforms: Windows, Mac and Linux (and other *nix). It was developed by the Mozilla Corporation until 2014 when development was handed over to the community. The Mozilla Foundation is now the fiscal home of Thunderbird. The Thunderbird Council, who lead the community effort, has begun hiring contractors through Mozilla in support of this venture and to guarantee that all vital services are provided in a reliable fashion.

You will join the team that is leading Thunderbird into a bright future. As a software engineer you will be maintaining and improving the existing Gecko-based Thunderbird but also pave the way for its transition to being based on web technologies.

The Thunderbird team works openly using public bug trackers and repositories, providing you with a premier chance to showcase your work to the world.

About the Contract
The Thunderbird project is looking to hire software engineers to help maintain Thunderbird. You’ll be expected to work with community volunteers, the Thunderbird Council, and other employees to maintain and improve the Thunderbird product.

This is a remote, hourly 6-month contract. Hours will be up to 40 a week. You will be expected to have excellent written communication skills and coordinate your work over email, IRC, and Bugzilla.

As a software engineer for Thunderbird you will
* Fix bugs and regressions and address technical debt.
* In collaboration with Thunderbird’s Engineering Steering Committee,
replace/rewrite modules to prepare Thunderbird for the transition to a
new platform.
* Maintain and improve Thunderbird to ensure that both nightly builds
and releases are always possible.
* Follow improvements made by Mozilla engineers for the Firefox platform
process and implement those for Thunderbird.
* Be a self-starter. In a large code-base it’s inevitable that you
conduct your own research, investigation and debugging, although others
in the project will of course share their knowledge.
* Work with both volunteers and employees across the world to fix issues.
* Collaborate with QA, Security, Localization, and Release Engineering
for coordinated code releases.

Your Previous Experience
Since we are looking to fill one or more positions, we are interested to
hear from junior and senior candidates who can offer the following:
* Solid knowledge and experience developing a large software system (7+
million lines of code).
* Solid knowledge of C++ as well as JavaScript, HTML and CSS.
* Ideally exposure to the Mozilla platform as a voluntary contributor or
add-on author with knowledge of XPCOM, XUL, etc.
* Some experience using distributed version control systems (preferably
Mercurial, Git would be acceptable).
* Some prior exposure to Python and build systems (preferably make)
would be beneficial.
* Experience developing software cross-platform applications is a plus.
* B.S. in Computer Science would be lovely, but real-world experience is

Check out the Thunderbird Source Code

Want to learn more about Thunderbird and get a sense of the project? You can find the source code and a short tutorial on getting started below:


Getting Started:

Next Steps
If this position sounds like a good fit for you, please send us your resume with a cover letter to

A cover letter is essential to your application, as it shows us how you envision Thunderbird’s technical future. Tell us about why you’re passionate about Thunderbird and this position. Also include samples of your work as a programmer, either directly or a link. If you contribute to any open source software, or maintain a blog we’d love to hear about it.

Please note that while the Thunderbird project is a group of individuals separate from the Mozilla Foundation that works to further the Thunderbird email client, the Mozilla Foundation is the Project’s fiscal home. The Thunderbird Council, separate from Mozilla, manages the Project and will direct the software engineer’s work.

The successful applicant will be hired as freelancer (independent contractor) through the Mozilla Foundation’s third-party service Upwork ( By applying to this job, you are agreeing to have your applications reviewed by Thunderbird contractors and volunteers who are a part of the hiring committee as well as by staff members of the Mozilla Foundation.

Mozilla values diversity. We do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status.

11 responses

Gregory Magarshak wrote on

Why didn’t Thunderbird, a product with 25 million users, have a full time developer until now? It would be helpful to know the history of the project and its development team / efforts.

Ryan Sipes wrote on

It did in the past. Of course, there was once a whole team of developers who worked on Thunderbird as part of Mozilla. Now that Thunderbird is its own entity we are hiring for the roles we need in order to drive development forward.

John wrote on

Thunderbird is already the best, by far! Everything can be improved though.

How people regularly use webmail and Outlook while staying sane is “ponderous, man, ___ ponderous.”

Ashton Kemerling wrote on

Why in the world is an organization as rich and experienced as Mozilla using Upwork for a “full time job”? That’s a horrible idea, and it will chase off a lot of the serious developers who would otherwise be interested.

Ryan Sipes wrote on

Thunderbird is its own kind of island right now. We are governed by the Thunderbird Council, which is elected and volunteer – and the Mozilla Foundation only serves as a legal entity in which we are able to keep our money as an org. They do not participate in our day-to-day operations.

corre alain wrote on

Importer les carnets d’Outlook 2007
Importation depuis Outlook et Eudora

Note : l’importation a été provisoirement désactivée sur les dernières versions de Thunderbird (38.0.0….45.6.0)


i need to work with my adress book and message from my outlook, very important

Alberto González Palomo wrote on

I’m considering applying for this as I use Thunderbird for all my email, wrote a couple of XUL applications years ago, and have an Upwork account, and the first thing I need to do is to see what the source code and build process looks like: I’ve built Firefox and FirefoxOS before, and it was not trivial.

Their post has nothing about that, and the Thunderbird page at Mozilla also has no “Developers”, “Source code” or similar link anywhere. That should be there at least in the page footer.

Ok, so here is the Mercurial repo and build instructions:

That link should be part of the job description.

The directory size (du -sh) is 148 MB after “hg clone”, and 5.4 GB after “./ checkout” before compiling.

Ryan Sipes wrote on

Good idea Alberto! I’ll include them in the post!

Alberto González Palomo wrote on

Forgot to add before my previous comment: (please edit if possible)

This comment was originally at HackerNews[1] but I realized that it might be more useful here.

Nep wrote on

I’m really glad Thunderbird is moving forward! it’s the best e-mail client ever! Thank you mozilla!

William wrote on

I would Thunderbird next release with unified account by default.
Thank you

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