A friendly fork of Thunderbird for Android (formerly K-9 Mail) that adds a biometric app-lock — require fingerprint or face unlock before the app can be opened.
Personal project. Core email functionality comes from upstream Thunderbird for Android; Relay Mail layers an app-level biometric lock on top.
Thunderbird for Android has no app-level lock. Relay Mail adds one, so opening the app (and seeing your mail) requires device biometric authentication — useful on shared or frequently handed-over phones.
- Biometric app-lock via AndroidX
BiometricPrompt, on launch and on return from background. - Otherwise tracks upstream Thunderbird for Android.
The fork is kept current and shippable with two CI pipelines:
- Weekly agent-assisted upstream sync. A scheduled GitHub Actions workflow runs every week: it pulls the latest Thunderbird for Android, attempts to merge it into the fork, and when merge conflicts come up, hands them to an AI agent that resolves them. The result is opened as a pull request for human review before it lands — so the fork stays up to date with upstream without manual rebasing.
- Automated release pipeline. A CI pipeline builds, versions, and publishes releases automatically.
Kotlin · Android · AndroidX BiometricPrompt · based on Thunderbird for Android / K-9 Mail.
Personal/experimental fork — build from source with Android Studio. Not published on app stores.
Based on Thunderbird for Android, Apache License 2.0. Retains upstream license and attribution.