Premium
Download Thunderbird Beta for Testers (f-droid version) 21.0 APK
Supports installation on external storage.
Target: Android 15 (API 35)
nodpi
What's new in Thunderbird Beta for Testers (f-droid version) 21.0
Changed:
- Animation setting now allows On, Off, and System Default options
- Modernized 'Fetching mail' account settings screen
- Modernized 'Composition defaults' screen
Fixed:
- Application could crash due to memory exhaustion
- Application could crash when rendering long messages
- Inline images were shown as attachments instead of displaying in message
- Server search results could disappear
- Manage Folders opened the wrong account instead of selected account
About Thunderbird Beta for Testers (f-droid version) 21.0
Premium
Features
* Supports multiple accounts
* Unified Inbox
* Privacy-friendly (no tracking whatsoever, only connects to your email provider)
* Automatic background synchronization or push notifications
* Local and server-side search
* OpenPGP email encryption (PGP/MIME)
Install the app OpenKeychain: Easy PGP to encrypt/decrypt your emails using OpenPGP.
Support
If you're having trouble with K-9 Mail, ask for help in our support forum.
Want to help?
K-9 Mail is a community developed project. If you're interested in helping to improve the app, please join us!
You can find our bug tracker, source code, and wiki at https://github.com/thunderbird/thunderbird-android.
We're always happy to welcome new developers, designers, documenters, translators, bug triagers and friends.
Thunderbird Beta for Testers (f-droid version) 21.0 variants
This release may come in several variants. Consult our handy FAQ to see which download is right for you.
Version:21.0
Uploaded:July 21, 2026 at 2:21PM UTC
File size:10.67 MB
Downloads:27
Version:21.0
Uploaded:July 21, 2026 at 2:21PM UTC
File size:10.67 MB
Version:21.0(39041) for Android 6.0+ (Marshmallow, API 23)
Uploaded:July 23, 2026 at 6:28PM UTC
File size:10.19 MB
Downloads:1
Version:20.1(39040) for Android 6.0+ (Marshmallow, API 23)
Uploaded:July 9, 2026 at 10:32AM UTC
File size:10.11 MB
Downloads:8
Version:20.0(39039) for Android 6.0+ (Marshmallow, API 23)
Uploaded:June 24, 2026 at 1:10PM UTC
File size:10.11 MB
Downloads:12
Version:19.2(39038) for Android 6.0+ (Marshmallow, API 23)
Uploaded:June 6, 2026 at 9:31AM UTC
File size:10.09 MB
Downloads:19
Version:19.1(39037) for Android 6.0+ (Marshmallow, API 23)
Uploaded:June 5, 2026 at 2:19PM UTC
File size:9.57 MB
Downloads:2
Version:19.0(39036) for Android 6.0+ (Marshmallow, API 23)
Uploaded:May 29, 2026 at 3:19PM UTC
File size:9.57 MB
Downloads:6
Version:18.0(39035) for Android 6.0+ (Marshmallow, API 23)
Uploaded:April 17, 2026 at 5:46PM UTC
File size:9.48 MB
Downloads:6
Version:17.0(39034) for Android 6.0+ (Marshmallow, API 23)
Uploaded:March 20, 2026 at 8:52PM UTC
File size:13.38 MB
Downloads:11
Version:21.0
Uploaded:July 23, 2026 at 6:28PM UTC
File size:10.19 MB
Downloads:1
Version:20.1
Uploaded:July 9, 2026 at 10:32AM UTC
File size:10.11 MB
Downloads:8
Version:20.0
Uploaded:June 24, 2026 at 1:10PM UTC
File size:10.11 MB
Downloads:12
Version:19.2
Uploaded:June 6, 2026 at 9:31AM UTC
File size:10.09 MB
Downloads:19
Version:19.1
Uploaded:June 5, 2026 at 2:19PM UTC
File size:9.57 MB
Downloads:2
Version:19.0
Uploaded:May 29, 2026 at 3:19PM UTC
File size:9.57 MB
Downloads:6
Version:18.0
Uploaded:April 17, 2026 at 5:46PM UTC
File size:9.48 MB
Downloads:6
Version:17.0
Uploaded:March 20, 2026 at 8:52PM UTC
File size:13.38 MB
Downloads:11
Version:16.1
Uploaded:March 3, 2026 at 10:56PM UTC
File size:12.76 MB
Downloads:14
Version:16.0
Uploaded:February 7, 2026 at 10:32AM UTC
File size:12.76 MB
Downloads:18
