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Download K-9 Mail 0.4 APK
What's new in K-9 Mail 0.4
- Sync logging limited to 24 hours
- Client certificate not displayed in SMTP settings
- "Enable debug logging" did not provide verbose logging
- Scrolling short email could trigger left/right swipe
- Landscape scrolling only worked in center of some screens
- IMAP folder operations broken with prefixes
- HTML/table rendering display broken
- Application crashed opening placeholder folder
About K-9 Mail 0.4
K-9 Mail is an open source email client that works with basically every email provider.
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 at forum.k9mail.app
Want to help?
K-9 Mail is now part of the Thunderbird family and remains 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 github.com/thunderbird/thunderbird-android
We're always happy to welcome new developers, designers, documenters, translators, bug triagers and friends.
K-9 Mail 0.4 variants
This release may come in several variants. Consult our handy FAQ to see which download is right for you.
Version:20.1
Uploaded:July 9, 2026 at 10:32AM UTC
File size:10.11 MB
Version:6.904(39004) for Android 5.0+ (Lollipop, API 21)
Uploaded:June 27, 2024 at 6:08PM UTC
File size:10.01 MB
Downloads:309
Version:6.903(39003) for Android 5.0+ (Lollipop, API 21)
Uploaded:June 24, 2024 at 12:55PM UTC
File size:10.00 MB
Downloads:61
Version:6.902(39002) for Android 5.0+ (Lollipop, API 21)
Uploaded:June 21, 2024 at 3:58PM UTC
File size:10.00 MB
Downloads:59
Version:6.804(38004) for Android 5.0+ (Lollipop, API 21)
Uploaded:June 7, 2024 at 4:18PM UTC
File size:9.75 MB
Downloads:321
Version:6.901(39001) for Android 5.0+ (Lollipop, API 21)
Uploaded:May 15, 2024 at 4:48PM UTC
File size:9.80 MB
Downloads:147
Version:6.900(39000) for Android 5.0+ (Lollipop, API 21)
Uploaded:May 15, 2024 at 2:48PM UTC
File size:9.80 MB
Downloads:24
Version:6.803(38003) for Android 5.0+ (Lollipop, API 21)
Uploaded:May 10, 2024 at 3:13PM UTC
File size:9.75 MB
Downloads:174
Version:6.802(38002) for Android 5.0+ (Lollipop, API 21)
Uploaded:April 5, 2024 at 6:25PM UTC
File size:9.71 MB
Downloads:254
Version:6.801(38001) for Android 5.0+ (Lollipop, API 21)
Uploaded:March 11, 2024 at 1:17PM UTC
File size:9.64 MB
Downloads:214
Version:6.800(38000) for Android 5.0+ (Lollipop, API 21)
Uploaded:February 29, 2024 at 3:50PM UTC
File size:9.61 MB
Downloads:230
Version:20.1
Uploaded:July 9, 2026 at 2:02PM UTC
File size:10.57 MB
Downloads:31
Version:20.0
Uploaded:June 23, 2026 at 2:13AM UTC
File size:10.11 MB
Downloads:52
Version:19.2
Uploaded:June 5, 2026 at 1:37AM UTC
File size:10.56 MB
Downloads:57
Version:19.0
Uploaded:May 29, 2026 at 12:34AM UTC
File size:10.05 MB
Downloads:35
Version:18.0
Uploaded:April 19, 2026 at 4:14PM UTC
File size:9.94 MB
Downloads:119
Version:17.0
Uploaded:March 24, 2026 at 1:32PM UTC
File size:14.01 MB
Downloads:74
Version:16.1
Uploaded:February 28, 2026 at 6:54PM UTC
File size:13.36 MB
Downloads:140
Version:16.0
Uploaded:February 3, 2026 at 6:14PM UTC
File size:13.36 MB
Downloads:89
Version:15.0
Uploaded:January 12, 2026 at 3:40PM UTC
File size:13.29 MB
Downloads:61
Version:14.0
Uploaded:December 20, 2025 at 7:58AM UTC
File size:12.93 MB
Downloads:104
