K-9 Mail
In-app purchases
star
99.7K reviews
PEGI 3
info
5M+
Downloads
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.
K-9 Mail is a 100% open source, privacy focused email client for Android
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 partiesLearn more about how developers declare sharing
- No data collectedLearn more about how developers declare collection
- Data is encrypted in transit
- Data can’t be deleted
Ratings and reviews
94.4K reviews
ear wig
- Flag inappropriate
April 2, 2026
i like this email client generally, especially as open source etc. once set up it generally works well. relatively easy to move between unified inbox and individual accounts. unified inbox only really useful when able to colour code accounts. delays in syncing, and especially sending, have gotten worse recently - emails often languish for ages in outbox for no reason, and have needed to eg use gmail to send an email alot more recently which defeats the purpose :/
2 people found this review helpful
Mozilla Thunderbird
April 3, 2026
Thanks for the review, and we are working on an issue with message sync, which is often causing emails to be stuck in the inbox, as a top priority! To color code your accounts, please go to Settings > [account] > General settings to change your account color, as well as your account avatar. We hope this information and advice helps.
Leigh Cook
- Flag inappropriate
November 7, 2024
I really don't like the latest update. I used to be able to see my list of named email accounts, but now that's been replaced by circles with 2 letters each, and most pairs are all the same, so I can't see which account eacg belongs to. Every time I open one up, the order of the circles changes. That's frustrating and time-consuming. It'd be helpful if you could drag the list to the right to see the account names. Sorry guys, I need to find a replacement now after loving this app for many years.
36 people found this review helpful
LNX
- Flag inappropriate
September 11, 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.
5 people found this review helpful
Mozilla Thunderbird
September 19, 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!
What’s new
K-9 Mail version 24.0
New:
- Signatures support HTML
- Reply offers Reply or Reply All
Changed:
- Long account names fit in two lines
Fixed:
- Compose selection invisible in light theme
- Status icons unreadable when selecting messages
- Recipient expander failed to collapse after edit
- Camera attachments could crash the app
- Save All saved each attachment with same file content
- HTML signatures could disappear after rotation
- Edit as new used wrong identity for queued mail
New:
- Signatures support HTML
- Reply offers Reply or Reply All
Changed:
- Long account names fit in two lines
Fixed:
- Compose selection invisible in light theme
- Status icons unreadable when selecting messages
- Recipient expander failed to collapse after edit
- Camera attachments could crash the app
- Save All saved each attachment with same file content
- HTML signatures could disappear after rotation
- Edit as new used wrong identity for queued mail
App support
About the developer
MZLA TECHNOLOGIES CORPORATION
mobile-appstore-admin@thunderbird.net
447 Sutter St
San Francisco, CA 94108-4601
United States
+1 650-910-8704
