K-9 Mail
In-app purchases
3.6star
100K reviewsinfo
5M+
Downloads
PEGI 3
info
About this app
K-9 Mail is an open source email client that works with basically every email provider.
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 https://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 https://github.com/thunderbird/thunderbird-android
We're always happy to welcome new developers, designers, documenters, translators, bug triagers and friends.
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 https://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 https://github.com/thunderbird/thunderbird-android
We're always happy to welcome new developers, designers, documenters, translators, bug triagers and friends.
Updated on
Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region and age. The developer provided this information and may update it over time.
No data shared with third parties
Learn more about how developers declare sharing
No data collected
Learn more about how developers declare collection
Data is encrypted in transit
Data can’t be deleted
Ratings and reviews
3.6
94.7K reviews
Jared Reid
- Flag inappropriate
18 July 2025
the app is okay, though I'm not a fan of the way the unified inbox is sorted, like it isn't the top heading in a folder with multiple inboxes. it's not intuitive. and, what about unified spam, trash, and draft folders? good UI and it works well enough without ads on your face.
18 people found this review helpful
Mozilla Thunderbird
18 July 2025
Thanks for your review! We're responding to feedback like yours, and our upcoming changes to the account drawer will also include a better experience for the Unified Inbox and other unified folders. You can read more and see screenshots in the Juny Mobile Progress Report at blog.thunderbird.net!
LNX
- Flag inappropriate
11 September 2025
It takes a bit of getting used to, but overall it works well. One major minus is that there is no option to print an email (or create a pdf). Why is something so basic not included?? The lack of print/pdf functions removes 2 stars! If ever there was something to improve on, this is it. I am still in shock. I don't want to have to email myself to a different email address on a different app to print an email. Please sort this out asap.
1 person found this review helpful
Mozilla Thunderbird
19 September 2025
We're so sorry for any frustration! K-9 Mail doesn't have a built in ability to print emails yet. While we don't have a date for when it will be added, we use feedback from reviews and connect.mozilla.org to help shape our roadmap and prioritize new feature development!
J Gilbert
- Flag inappropriate
24 October 2025
0 stars!! Used to be the best, now it's another crAPP sellout. It's nothing but a glorified clone of Thunderbird! Notification sounds no longer play, instead I only get silent notifications even though I DO NOT have DND or "Quiet Mode" turned on & no amount of troubleshooting works. Also I now have to expand the "Saved" folder for my AOL account EVERY. SINGLE. TIME I open K9 to view my sub folders when in previous versions, they were listed individually. UNINSTALLING!
39 people found this review helpful
What's new
- 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
- 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
App support
About the developer
MZLA TECHNOLOGIES CORPORATION
mobile-appstore-admin@thunderbird.net
149 New Montgomery St Fl 4
San Francisco, CA 94105
United States
+1 650-910-8704
