What is Thunderbird for Android used for?

Thunderbird for Android is an open-source, privacy-focused email app for managing multiple accounts, based on K-9 Mail. It is a good fit for managing several mailboxes on Android and replacing a closed-source email client.

Is Thunderbird for Android open source?

Yes. Thunderbird for Android is open source under the Apache-2.0 licence. Its source code is on GitHub at thunderbird/thunderbird-android and is written mainly in Kotlin.

Is Thunderbird for Android free?

Yes. Thunderbird for Android is open source, so the software itself is free to use.

Can I self-host Thunderbird for Android?

Yes. Thunderbird for Android can be self-hosted on your own server or infrastructure; there is no official hosted version.

What is Thunderbird for Android an alternative to?

Thunderbird for Android is an open-source alternative to Gmail, Microsoft Outlook, Spark Mail and Canary Mail. Other open-source alternatives to Gmail include FairEmail, Mail0 and Tuta.

Is Thunderbird for Android actively maintained?

Yes. The most recent commit to Thunderbird for Android was on 2 October 2026. The project has 14k stars on GitHub.

Thunderbird for Android: open-source alternative to Gmail

About Thunderbird for Android

Thunderbird for Android is an open-source email app for Android that manages multiple email accounts from one place, with an optional Unified Inbox. It is the Android edition of Thunderbird, developed by a team of developers with help from a community of volunteers, and it is based on K-9 Mail, formerly the project's name. It is written in Kotlin.

The project states that Thunderbird never treats private data as a product. The app can be installed from Google Play or F-Droid, in stable or beta versions, from GitHub releases, through FFUpdater, or with Obtainium. The beta channel gives early access to features still under development, and signing certificate fingerprints are published in the security document.

Help comes from a knowledge base, a support forum and a GitHub issue tracker, and feature ideas are discussed on connect.mozilla.org. Release notes describe what changed in each version. The app is released under the Apache 2.0 license and runs on the phone itself, connecting to the email providers you configure.

Key features

Multiple email accounts in one app
Unified Inbox option
Stable and beta release channels
Available on Google Play and F-Droid
Based on K-9 Mail
Written in Kotlin

Good fit for

→Managing several mailboxes on Android
→Replacing a closed-source email client

Built with: Kotlin
Tags: email; android; mail-client; k-9-mail; thunderbird; privacy; kotlin; mobile-app

Thunderbird for Android: questions and answers

What is Thunderbird for Android used for?: Thunderbird for Android is an open-source, privacy-focused email app for managing multiple accounts, based on K-9 Mail. It is a good fit for managing several mailboxes on Android and replacing a closed-source email client.
Is Thunderbird for Android open source?: Yes. Thunderbird for Android is open source under the Apache-2.0 licence. Its source code is on GitHub at thunderbird/thunderbird-android and is written mainly in Kotlin.
Is Thunderbird for Android free?: Yes. Thunderbird for Android is open source, so the software itself is free to use.
Can I self-host Thunderbird for Android?: Yes. Thunderbird for Android can be self-hosted on your own server or infrastructure; there is no official hosted version.
What is Thunderbird for Android an alternative to?: Thunderbird for Android is an open-source alternative to Gmail, Microsoft Outlook, Spark Mail and Canary Mail. Other open-source alternatives to Gmail include FairEmail, Mail0 and Tuta.
Is Thunderbird for Android actively maintained?: Yes. The most recent commit to Thunderbird for Android was on 2 October 2026. The project has 14k stars on GitHub.