• Development

Mobile Progress Report: June 2026

The past month was busy; the theme was evolution. We went into this quarter with our own ideas for what we wanted to accomplish. However, our users had better ideas. With the release of Thunderbird’s own mail service, Thundermail, the need for a better account settings import process across our services and apps became vital.

We have also heard from our users about issues they had with syncing, notifications, bugs, and more. As such, we refined our roadmap, because the goal is always a better, safer, more private email client, and delivering that experience is more important than any foregone projects. Our roadmap can change, but our goal to deliver the best cannot.

Android

On Android, our focus turned to our import function through a QR code. This helps transfer settings from Thunderbird desktop to mobile. We also ensured that it would work for our new Thundermail project. This allows our early Thundermail users to quickly move their accounts to the Thunderbird mobile app. Additionally, we merged fixes for importing accounts, getting the avatar monogram to match the account immediately after setup, and new translations. 

We also began some exploratory work on one of our biggest upcoming projects. Our users have been clear about a recurring issue that they want resolved. Notifications. Notifications on an email client are tricky, especially one like ours, where we support so many different services. Users report not receiving notifications for newly delivered emails, even when polling or push are enabled, notifications appearing improperly in the notification shade, and many others.

We broke this up into two projects. The first priority will be to work on the quick fixes. These are bugs discovered through reports or our own testing. These fixes won’t require an entire refactor of our sync, notification, or database features, allowing us to address user concerns without launching a big project. But we are intending to launch a big project. We’ll do whatever we have to in order to make notifications work as expected. That’s the second planned project, to consider larger performance improvements, even a full refactor of sync, notifications, and the app database if we have to. Prompt email delivery is essential. We’re going to ensure Thunderbird becomes a trusted client for rapid email syncing and notification. 

We’ve also begun investigating potential feature flag options. While we currently have internal feature flags for our debug builds, we’re looking into options that we could host ourselves to ensure privacy, while also allowing us to enable features more quickly, without a full update. This would also allow us to roll back any changes that introduce issues without an app update. We hope it can allow us to launch products more quickly, and potentially even give end users more control over the features they have enabled. 

iOS

The iOS app is coming along nicely, with the core libraries (IMAP, SMTP, and MIME) set up. We’re working on how to store account data in the local database, as well as starting the email compose functionality. iOS will have a WYSIWYG editor for new messages, just as you’ve come to expect from other email clients. Also, this week has been busy with WWDC and understanding how the new tools and operating system will affect and improve our roadmap, mostly in the user interface.

Our Open Source Community

We wouldn’t be who we are without the open source community at our core. Open source isn’t just how we build software, it’s how we plan, make, and grow. Our community has a say in what we do, which includes making changes, bug fixes, suggesting new features, and voicing complaints – this insight from you is our greatest strength. Over the past month, we’ve heard requests for new features, bug fixes, and changes, and we’ve adapted our plans for the rest of the year to focus on this. And hopefully deliver them in more bite-sized pieces.

First, the community has helped drive our upcoming projects. From notifications to investigations into spam filters, our community is helping drive our objectives. Our priorities and our roadmap have shifted thanks to that feedback. With our community having our back, we’re making the best email client available on iOS and Android, and can’t wait to deliver these improvements. We’re listening and working on these highly requested changes. 

A notable contribution from our community came in the form of a fix for our notification widget. The text wasn’t scaling for users with different font size settings. This is a serious accessibility issue. Fortunately, a contributor pushed a fix which ensures the font size scales with the system. We’re grateful for this help, and it’s a perfect example of how we build better together. 

Becoming a Contributor

Interested in contributing yourself? It can be tough to figure out where to start or how to go about it. Soon starting development on the Thunderbird for Android app will be easier than ever. We’re moving our documentation around and adding templates and examples to make everything from requesting new features to working on bug fixes, and even documenting your changes easier. We’ve also added a new pull request template to help you write a detailed message explaining your pull request. This includes letting us know if you’ve used AI in the development and to what level it was used.

One note to say with contributions, given our limited team size and resources, we are focusing our efforts on the top items on the roadmap first and foremost. Second, we will spend a couple of weeks solving the largest impact bugs. Then we will spend a week or two supporting what contributions help resolve bug reports or align with our roadmap. We are intrigued about how AI can help us in these efforts, but we are also vigilant about the quality of the code. Potential contributors need a strong understanding of what they are contributing. This means being able to change, improve, and support the code they contribute in the future.

We have just three engineers on each of our iOS and Android teams. We’re supported by wonderful designers and product folks, but we also couldn’t do it without your support. So, thank you. We’re doing our best to make a great product, and with your help, contributions, donations, bug reports, feature requests, and enthusiasm, we’re able to do it better than ever. Thanks for checking in with us!

– Danielle G. (she/her), Senior Android Engineer