K-9 Mail

Name: K-9 Mail
Availability: InStock
Rating: 3.292452812194824 (99792 reviews)
Author: Mozilla Thunderbird

Mozilla Thunderbird

In-app purchases

3.3

99.8K reviews

5M+

Downloads

PEGI 3

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.

Updated on

Mar 10, 2025

Data safety

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

3.4

94.6K reviews

A Google user

January 12, 2025

I'm a long time user of K9. Latest update (April23) seems to have increased the message subject area significantly... Now taking up nearly half of my screen with white space. I can't find any way of reducing this. Otherwise a great app. Just please stop meddling with the UI. V5 was the best! So, in Jan 25, I've settled down to the changes and my one star review seems a bit harsh. I'm actually very happy with the way that K5 works with multiple accounts and that it is ad and clutter free.

14 people found this review helpful

Steve McKinty

November 21, 2024

Have to agree with the other recent reviews, the new UI is terrible. Washed out, hard to see the difference between read and unread, etc. Very much a case of fixing something that wasn't broken. I've uninstalled it and reverted to the previous release for now, looks like I need to find an alternative. I originally picked k9 because it was clean and simple, like the Thunderbird I used on desktops and laptops, but just ss Mozilla have ruined Thunderbird, K9 has been wrecked as well. Shame.

4 people found this review helpful

Jeremy Hicks

May 12, 2024

Generally good, but there is a bug. When I forwarded an email containing an attachment, a message was displayed saying "This attachment cannot be forwarded because it contains...". It disappeared after a couple of seconds so it was easy to miss, and there was no obvious way of displaying the full message so the content was meaningless. The app then allowed me to forward the message, without the attachment, and without my knowledge or consent.

7 people found this review helpful

Mozilla Thunderbird

May 21, 2024

Hi Jeremy, thank you for taking the time to report this so we can investigate the problem. Can you tell us what kind of attachment the email contained?

What’s new

- Basic support for Android 15
- Add a link to the support article when signing in with Google
- Account setup attempts email provider's autoconfig first, then falls back to ISPDB
- Updated translations for multiple languages
- The changelog now properly displays release versions
- A wrong translation of the app name has been fixed
- Dependencies have been updated to fix a couple of bugs

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