K-9 Mail

K-9 Mail is a 100% open source, privacy focused email client for Android

App info

Version :

9.0

Category :

Communication

Update :

March 10, 2025

Installs :

9,366,615

Developer :

Mozilla Thunderbird

Requires Android :

Android Varies with device

Content Rating :

Everyone

Get it on :

Download APK

App description

Android App Analysis and Review: K-9 Mail, Developed by Mozilla Thunderbird. Listed in Communication Category. Current Version Is 9.0, Updated On 10/03/2025 . According to users reviews on Google Play: K-9 Mail. Achieved Over 9 million Installs. K-9 Mail Currently Has 100 thousand Reviews, Average Rating 3.3 Stars

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.

We are currently offering version 9.0. This is our latest, most optimized version. It is suitable for many different devices. Free download directly apk from the Google Play Store or other versions we're hosting. Moreover, you can download without registration and no login required.

We have more than 2000+ available devices for Samsung, Xiaomi, Huawei, Oppo, Vivo, Motorola, LG, Google, OnePlus, Sony, Tablet ... with so many options, it’s easy for you to choose games or software that fit your device.

It can come in handy if there are any country restrictions or any restrictions from the side of your device on the Google App Store.

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

Rate and review on Google Play store

3.3

99,771 total

5 42.6

4 11.5

3 9.6

2 9.6

1 26.7

Total number of ratings

Total number of active users rated for: K-9 Mail

Total number of installs (*estimated)

Estimation of total number of installs on Google Play, Approximated from number of ratings and install bounds achieved on Google Play.

Recent Comments

DrZaius

I've used this app since 2016 but I had to stop on 2020 when main email providers ditched support for user/pass authentication. Since K9 lacked support for oauth, I was obliged to switch to samsung mail. I'm coming back now looking for a specific feature that samsung mail doesn't have : multiple identities on the same account. For now, I can really see that a lot of work was put on the user interface, which is cool considering that the old one was not very ergonomic. I'll rate 5 if I switch.

A Google user

Great app, nice and fast interface. I don't understand why their are so any bad commentaries recently saying this is "abandonnedware". The app works great for me, no sync problem. The interface looks good enough for me, not outdated at all and it is very responsive. It lacks a few options like a delay before the email is actually sent, or automated support for calendar invites but it is acceptable.

Dan Gilliam

No. Just, no. It went from 5 stars to 1 in one version. The new interface is clunky and cumbersome, and unintuitive. The old interface was perfect, especially if you have multiple accounts. Please bring it back, make a legacy version, something. I am one inch away from going to another app and chalking this into the "Used to be amazing" list.

Mike Smith

Honestly this new update stinks, like most others are saying the account interface is worse now. But not only that when I reply to emails it keeps hanging on a black screen then crashing, this was never a thing on the previous version so why so this to what was a great email app. Update, literally can't reply to an email, I've restarted the app, cleared the cache, rebooted the phone. I don't want to clear the data as I'll have to set it up again as I doubt an export will solve it. Help!!!!!!!!

Leigh Cook

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.

Jim Rebensdorf

New interface is awful....now clicking on the hamburger menu shows a pill-style interface, and I can't tell which account I am looking at unless I click through each pill, one at a time. Just an awful change. Not sure how this got past UA testing, but at least give us an option to reskin if there is going to be such a mess to deal with, especially for users who do have mtiplr email accounts.

SANDY

New modern look, if can add picture to differ each account would be better, the only inconvenient is there is no way to poll all folder. On previous version, there is poll class on "fetching setting" which allow us to poll all class, I usually use this setting to refresh all folder once in a while, but there is no such setting on new version. The "sync button" above setting button, looks like only sync inbox, if it could sync all folder (despite each folder setting) it would be great, thanks

Manuel Gisbert

The Thunderbird redesign is a step back in UI/UX. I tried the TB beta a while ago, and reverted back to K9. Sadly now K9 updated to the same design. Two observations: I think message list has lower density, ie fewer messages per page, that's my recollection when I compared both. Moving the account list to the left with two character labels is a disaster for user with multiple accounts on same domain. I have 6 accounts on same domain, all showing as MA. Old drop down was way better.