K-9 Mail APK

Version 5.717 - com.fsck.k9
Last updated: 2020-07-05

K-9 Mail apk

APP Information

Download Version 5.717 (27017)
Apk Size7.75 MB
App DeveloperK-9 Dog Walkers
Malware CheckTRUSTED
Install on Android5.0 and up
App Packagecom.fsck.k9.apk
Website https://k9mail.github.io/

Download K-9 Mail 5.717 APK

App Description

K-9 Mail is fsck,communication,mail, content rating is Everyone (PEGI-3). This app is rated 4.33 by 40 users who are using this app. To know more about the company/developer, visit K-9 Dog Walkers website who developed it. com.fsck.k9.apk apps can be downloaded and installed on Android 5.0 and higher Android devices. The Latest Version of 5.717 Available for download. Download the app using your favorite browser and click Install to install the application. Please note that we provide both basic and pure APK files and faster download speeds than APK Mirror. This app APK has been downloaded 189685+ times on store. You can also download com.fsck.k9 APK and run it with the popular Android Emulators.

K-9 Mail is an open source email client with support for multiple accounts, search, IMAP push email, multi-folder sync, flagging, filing, signatures, BCC-self, PGPMIME & more! 

K-9 supports IMAP, POP3 and Exchange 20032007 (with WebDAV).

Install the app "OpenKeychain: Easy PGP" to encryptdecrypt your emails using OpenPGP.

K-9 is a community developed project. If you're interested in helping to make the most popular open source email client on Android even better, please join us! You can find our bug tracker, source code, mailing list and wiki at https:github.comk9mailk-9
We're always happy to welcome new developers, designers, documenters, bug triagers and friends. 

If you're having trouble with K-9, please report a bug at https:github.comk9mailk-9 rather than just leaving a one-star review. We don't mind you telling the world that you're frustrated, but if you use our bug tracker, we have a better chance of fixing whatever's giving you a hard time.

You can find K-9's release notes at: http:bit.lynew-k9

(People sometimes call K-9: K9, K9 Mail, K-9 Email, K9 Email, K9 E-Mail, k9mail or k9email.) 

App ChangeLog

  • - Further improvements to encryption user experience
  • - Added ability to forward a message as attachment
  • - Improved the way we display text/plain messages
  • - Improved rendering of right-to-left text
  • - Fixed bug that caused draft messages to be lost
  • - More bug fixes

App Screens

K-9 Mail App Screen 1K-9 Mail App Screen 2K-9 Mail App Screen 3K-9 Mail App Screen 4K-9 Mail App Screen 5K-9 Mail App Screen 6


requires following permissions on your android device.

view network connections
Allows the app to view information about network connections such as which networks exist and are connected.

Allows access to the list of accounts in the Accounts Service.

full network access
Allows the app to create network sockets and use custom network protocols. The browser and other applications provide means to send data to the internet, so this permission is not required to send data to the internet.

read your contacts
Allows the app to read data about your contacts stored on your phone, including the frequency with which you've called, emailed, or communicated in other ways with specific individuals. This permission allows apps to save your contact data, and malicious apps may share contact data without your knowledge.

read sync settings
Allows the app to read the sync settings for an account. For example, this can determine whether the People app is synced with an account.

run at startup
Allows the app to have itself started as soon as the system has finished booting. This can make it take longer to start the phone and allow the app to slow down the overall phone by always running.

control vibration
Allows the app to control the vibrator.

prevent phone from sleeping
Allows the app to prevent the phone from going to sleep.

Older Versions

More Android Apps to Consider

Google Play Reviews

  1. Logan Rathbone-avatar

    I'm largely going to echo Michael Fox's review. I have used this app on various versions of Android, numerous Android phones, as my mobile mail daily driver for nearly a decade. It has never let me down. I'm running stock Android 10 on an Umidigi phone at this point. Yes, it gives you an error that it may not work correctly on Android 10, but I have had no issues thus far. I'm sure a new stable release will be coming soon; development on GitHub is still very active. I too run my own IMAP server. At least when I started looking nearly a decade ago, finding a really solid IMAP mail client for Android that properly supported IMAP IDLE was like finding a needle in a haystack. Luckily for me, K-9 was that needle. IMAP IDLE support continues to work for me on K-9 with Android 10. I just got the phone and all battery optimization settings are just the defaults. Again, this is STOCK Android; I have no way of knowing how other phone manufacturers may be butchering their Franken-Android OSes. I don't know if other email apps work as well as K-9 for what I need. Frankly I don't really need to know, because K-9 works great, and is lightweight and open source to boot. I have no use for pointless features like "unified inbox" but I suppose it's good that they're there for those that demand such silliness. All I want is an email client that talks to my IMAP server and does it right. I want it to be simple and stay out of my way, but let me delve deep into the settings and options when I need to. K-9 Mail is that app for me.

  2. Shiva Baba-avatar

    ios I grew tired of the stock email app and wanted something different. All the other apps seem to track personal information or have other undesirable features. While people make complaints in some of the reviews about a lack of functionality, it's overall an effective email client and it's free. Yes some of the features require a bit more touches than previous apps, but this is been my default app for a long time and I really enjoy it and appreciate the offering.

  3. Chris Mailloux-avatar

    gmail Unbelievably good. I have an old S4 that chugs slowly using the Gmail app and sought a more lightweight client. So I was amazed just how fast and featurful K9 is. It does everything I need it to do and leaves no feature compromises while also being very fast and snappy on my phone. 10/10.

  4. T Schilling-avatar

    android 10 Not the perfect email app; takes a lot of time to configure if you have a lot of accounts and folders. Biggest wish is that settings could be applied to a group of folders at once, instead of having to do each setting on each folder individually. That said, I prefer K-9 over other apps I've tried. Would pay for a "pro" version if it had more desktop-like features (like Thunderbird).

  5. johannes-avatar

    app Update March 2020: The app has problems to synchronise with the online folders. It keeps trying to sync for days (IMAP). Also, emails with attachments end in an eye message and usually don't go out. The app is rather unusable in the current its state. Original 5-star rating: Does not drain the battery, no ads, unified inbox, great controls down to each folder in each email account. 5 stars!

  6. Glenn Reffin-avatar

    drucken Ok basic email client but it isn't very user-focused where it is impossible to move multiple emails to spam or other folders, or delete emails in one go. It can be mind numbing especially when dealing with many email accounts. Also, the interface is very old fashioned and could do with a major overhaul. Now using a different client.

  7. Ralph Stele-avatar

    für ios A little quirky but more trustworthy than many other apps on the Store - and that yrust in privacy is worth a lot. I still have the issue of spurious folders (INBOX.Trash etc.) appearing, with no mechanism to delete them. I also agree that the menu design is opaque to say the least. Finding a setting is "poke & hope" at best.

  8. SAM H-avatar

    exchange I've tried a dozen times to get the k-9 app to work with my Yahoo mail account but it just doesn't want to add it. It gives the 'username and password incorrect. (Command: *sensitive*; response: #2# [NO, [AUTHENTICATIONFAILED], LOGIN invalid credentials])' message, while I KNOW i am NOT entering the wrong password. I've tried the manual imap configurations from yahoomail sites and the K-9 site as well. Any fix to this issue?

  9. John F-avatar

    push Used for years but must look around again now I'm adding a second account. K9 has a crazy nest of menus, hard to find the setting you want, confusing folders, no dedicated help file, making it a PITA. OTOH, I have found it can wrap & display text better than some, where only option was to zoom in & pan around, & I don't want to lose that. A much simpler UI & menu would transform this into an unbeatable app I'd even pay for, but it's like herding cats. Last update to K9 was 2018, not acceptable.

  10. Alyson Abramowitz-avatar

    Alyson Abramowitz


    passwort ändern Dont download if you have V10. I loved this app but since the upgrade it crashes dozens of times daily. I can't get a single response from the developers. This used to be a 5 star app.

  11. Euclid Megara-avatar

    The only thing that would make this abetter email client would be the ability to view all emails in plain text, not HTML. Otherwise it's great.

  12. Daniel Palacios J.-avatar

    Daniel Palacios J.


    Just got Android 10, and the app is starting to look and feel old and slow. If not updated soon, I will start looking for an alternative. It worked great when it was kept up to date

  13. Gennady Proskurin-avatar

    Gennady Proskurin


    Sometimes in cannot send emails at all, message is stuck in outbox. Completely unacceptable for email app, I had to switch to another app because of this bug.

  14. I am ion's Cat-avatar

    Like many others I've used this app since I started email on my phone. I still have it on my phone I use for music. But it just doesn't work anymore for me. I can get it to sync manually only. I've switched to blue mail from another review here. I will still pray the developer updates it back to working status because I love it! But for now I have to use something else. Please restore k-9, I'll come back instantly.

  15. Michael Fox-avatar

    I've used this app for years and it's made IMAP accounts a breeze. I think most of the reviews on here are due to Android stopping the app from working properly, or using services that don't work properly. By turning off the battery optimization for this app, and using a proper server that supports IMAP IDLE connections, I receive a notification instantly. Hosting your own email is getting harder and harder these days. This app is extremely helpful. I hope the developer stays motivated.

  16. A Google user-avatar

    Used it for many years, and very happy with it. No ads, dark background to reduce battery use, can manage multiple accounts, set up signature files, set frequency of checking for messages separately for each account, auto BCC myself on responses to keep a copy of sent mails for my computer. I use POP and leave mail on server until downloaded to my computer, so no synching. Notifications are prompt. I wish I could link text & sometimes can't open PDFs til I download them, but no other issues.

  17. Neil Hallam-avatar

    I've used K9 for years on different phones, it's a simple app and straightforward to setup and use, always been happy with it. Recently installed it on a new phone, and syncing is disabled. I've tried everything I can to try to fix it but to no avail. From the looks of many posts online, it seems the developers know there's a problem but aren't in a rush to fix it. So I'll be using a different email client from now on.

  18. Pirate Jack-avatar

    Very often is mentioned that "Sync is disabled" even tho it should be all fine since I checked everything on my own and with my Email provider.

  19. S Russell Berckmoes-avatar

    S Russell Berckmoes


    I've been using this for about six years now. Great email client. It's beginning to feel a bit stale, and they haven't updated it for a bit. Now with Android 10, I get a message from the app saying it was built for an older version of android. Still working fine other than that. I may start looking for another email app if they don't fix this soon.

  20. Robert P-avatar

    I have used this app for years and basically love it. Unfortunately, recent changes to Chrome OS seem to have broken several things including keyboard mapping. I submitted the issue to the Chrome OS folks, but submitting a bug report is a bit more obscure for K-9 Mail. Hope this gets fixed soon.

  21. Pete A.-avatar

    Previously served me very well. Now, on Samsung Galaxy Note9 with UI 2 running Android 10, it doesn't recognise my e-mail log-on details (which I made sure were entered correctly). Ho hum, back to using Yahoo's flaky app.

  22. Sean Kim-avatar

    Tried to add exchange account and it asked for pop, imap, or something else. Tried all of those options and all of them led to empty inbox. Didn't even get to my company login page or okta mfa. On top of that, ui did not show clearly where i could log off and retry with different account.

  23. श्री सायि -लक्ष्मण-avatar

    श्री सायि -लक्ष्मण


    Best free mail app so far! But re-installing app, unfortunately, results in loss of locally stored e-mails. So the app could be improved even further by adding "Save my mails to sdcard" -option. (But the format of saved messages must be very universal, like html, or rtf, or even plain text. So we can edit etc. easily - even with other apps. I personally like to store all my important mails as one MsWord document). Also, there is a bug: "Next poll ... hours ago". (NEXT = later, not ago).

  24. Nucleus Rhyme-avatar

    Ugly, un ergonomic menus, an app that has its roots in the Windows 95 era. Still, it does its job well, it has no spam, eats few resources, and once configured it simply keeps going.

  25. A Google User-avatar

    Not as fancy as newer apps but served me well for 10 years. Highly reliable and never crashed on my two devices.

  26. Kevin Andreoli-avatar

    Works great on the latest Android but how long for? It is sadly obviously no longer being developed as no updates since 2018.

  27. Caps CC-avatar

    Near perfect email clent. It can backup your Settings including multiple accounts and import to a new device: it does not save the pwds (for security, obviuosly), but I suggest it could save the accounts pwds in the Settings backup encrypted with a master pwd. A good app does not need continuous updates! Congratulations to the developer.

  28. David Wilcox-avatar

    One of the best mail applications I have ever used. I have never had a problem and I suggest it all of the time to my coworkers so that they can separate their work email from their person all life. Also k9 is ther best robot dog ever.

  29. Gary M-avatar

    Can handle my mail server's unusual settings. So many mail apps can't connect to anything but the big name services.

  30. R Howard-avatar

    I have been looking for a decent android email app for a long time. Finally found K-9 Mail which is highly configurable. It allows me to configure it so when I delete an imap message it only deletes it on the phone. This allows me to download all my email onto my computer at home and use filters to move it to local folders. Other email apps made this email flow difficult to perform.

  31. Peter Tomov-avatar

    Works just like a proper email client should. I love it. Although sometimes the controls may seem a bit clumsy... It just takes getting used to.

  32. Martin Neumann-avatar

    Great app able to handle my many accounts efficiently. I love most the account overview. It gives me with a quick glance on which accounts I've new or starred email. It allows to quickly jump to only new, starred email, or just go to the folder view. Besides those technical features it is open source and ad free.

  33. David Spencer-avatar

    I have been using this app for many years with the latest update come out there seems to be many changes, once I delete a message, it is not surfacing up in the trash folder anymore , I'd this change deliberately done ?

  34. Alius S-avatar

    Seems that development is abandoned. Used to be a good mailing and pgp client, unfortunately bugs are no more fixed

  35. Dave Brown-avatar

    Great email app (I use POP3). Solved sync problem on Galaxy J3/Android 9. Tap settings (pull down top of screen and tap gear wheel) then tap Device Care - tap Battery then Tap Battery Usage - tap Screen then Tap Optimise Battery then Tap Dropdown menu (at top) & tap All. Now find K9-Mail and turn off optimisation Try it - (setting is well hidden).

  36. Erik Kowal-avatar

    The app refused to accept my (correct) email settings, and also could not (despite the description of the app) be configured to save emails to my external SD card as promised, which was the only reason I installed it in the first place. A disappointing waste of space and time. I have since uninstalled the app.

  37. Wayne Louie-avatar

    Highly configurable, works well, only app that seems to integrate with PGP keys.

  38. Sven Mantwill-avatar

    Great Email-App - I have been a user since 2012 and I still love it. This week I got a new phone and the first thing was to install K-9 Mail again and to transfer the profile from my old phone. A big thank you to the team developing this open source app in their free time.

  39. JP S-avatar

    Sync is disabled, unable to re-enable it. Cannot adjust battery optimization settings for this app. App gives notification that it's made for an older version of Android, I have Android 6.0.1. Developer must have given up on updating this app which sucks because I used it for years before.

  40. Gavala Chad-avatar

    Used K9 over 4 years on various phones and it's never failed even on the latest Android version 9 / Pie. Easy to set up IMAP. Never an annoying request for money as I see on other mail app reviews. It just works and works bloody well.

  41. Tim Doehler-avatar

    Had horrible experience in the part with this app, but frankly all Android email apps are garbage. Thought I'd try it again: Nope. 1) error about working with Android 10; 2) won't authenticate with Google for my Gmail. If you don't work with Google on TWO levels, What business do you have making an Android app? ¯\_(ツ)_/¯ Edit: just got an email from Google saying they blocked an unsecured attempt to log in to my email. WOW. You know it's bad when Google blocks someone else because of security!

  42. yudsky 27-avatar

    Still, love the simplycities and lightweight of this app. I fix the sync probelm with pnf like app. This app would be great if the mail that show on widget can be sorted by unread/read status

  43. Bradley Lawrence-avatar

    Bradley Lawrence


    Anyone who says this app is anything less than perfect.... Is almost certainly wrong. I have used this for like a decade without even a hint of problems.

  44. Jude DaShiell-avatar

    what a mangey mutt! In account sign up the program uses people's entire email addresses as usernames and doesn't allow those fields to be cleared. With providers other than gmail, a username may be everything to the left of the at sign and not the whole email address and this app will not accommodate that requirement.

  45. César Gonçalves-avatar

    César Gonçalves


    First time using. Works well with Android 9. No ads, lightweight, good dark theme.

  46. Charles Goddard-avatar

    Charles Goddard


    Simple to use email app with a small footprint and easy on the resources. Well done!

  47. Rusty C-avatar

    Works well, handles more than one email address. It's a keeper.

  48. Simone Proia-avatar

    Great and very complete Email client App. Suitable for end users who wants to keep it simple but rich of features for more advanced users. It has been my favourite one for years.

  49. Ruth Morris-avatar

    I love this email app for so many reasons. It's flexible in options and aesthetics is the best. However, the for the past two phones and operating systems, its polling function is completely unreliable. There seems to be no rhyme or reason to polling to randomly becoming disabled, then showing it's working again, without making any changes to settings. Very aggravating. Too bad. Hope they get it fixed once and for all.

  50. George B-avatar

    Won't work on gmail accounts unless you check to "Allow less secure apps" to run on my phone. That means ALL less secure apps run automatically if I just want to allow k-9 to run a gmail account. Either the k-9 developers need to make their app more secure to pass Google's standards or Google needs to let us individually choose a "less secure app" one at a time to run versus just doing a blanket ALL less secure apps can run just to allow k-9 to work.

  51. Swarnendu Maiti-avatar

    Swarnendu Maiti


    I really love the app in my privacy centric life. Specially the Dark Mode is so awesome & cool. I would like to request one feature, please allow us an option to 'Print' a specific Email to save as pdf or directly print it from the app itself. Thank you. ❤️ from India 🇮🇳

  52. Chuck Ray-avatar

    Used to be great and I used to love it. But it's become increasingly unreliable in the last year. It drops messages (they're sitting in my inbox on other computers, but k9 never gets them), it doesn't synchronize the read and archived status to the server for hours, it has trouble sending emails, and sync never works (always disabled) It was a great open source project but I'm afraid I'll have to look elsewhere now. I appreciate all the work the community has put into the app, so long!

  53. Jul Ius-avatar

    Good mail app. Not incredibly modern UI but very functional.

  54. St St-avatar

    After fighting my way through the settings and having it behave like I wanted it to (being immediately notified when an email arrives, actually ...) the app started changing it's behavior out of the blue after working well for a few months. All of a sudden, I get incoming email notifications only after activating the screen (taking the phone out of sleep). Btw, I always keep the app running in the background. Sorry but I don't like inconsistent apps. So I am looking for an alternative.

  55. Yasser Sedky-avatar

    Very good App. Missing two stars for: - Moving the attachments to the bottom of received email. So, you have to scroll through long trails to download the attachments. (Was at top in previous versions). - Not allowing inline comments when replying to emails. Please fix this in next releases, at least bring back the attachments to the top.

  56. Mike McCord-avatar

    Used this app for years. Now, though, I get constant notices saying that k-9 mail is over-using the battery. Most recently it used 8% of the charge in less than a half hour. So I am constantly having to restart my phone. But then it happens again an hour later. I'm here at the playstore to find another email app so I can delete K-9 Mail. Samsung S8+.

  57. Softech Systems-avatar

    Softech Systems


    Awesome ! The "Push" notifications are VERY fast. I love the uncomplicated layout. Has options for leaving email on server after deleting on phone, custom signatures, and lots more. If you have an Android phone this is a must and no, I do not work for nor am I affiliated with K-9 :0) This is the 3rd app I've tried and I'm staying with this one.

  58. Michael Rupp-avatar

    Damn! This is the best mobile email client ever! I'm managing 14 accounts with it. it's very well organized and remarkably configurable. Setup is easy for new users; email address and password is all you need to get going. I tweak lots of things. I just learned how to secure with OpenPGP yesterday and today i can send encrypted message from my phone!

  59. B. W.-avatar

    This app used to be great. I have used it for years. Now it has been terrible. Keep getting "sync disabled". And it has started to give me "authorization failed" on some of my accounts. Have deleted those accounts and put them back. They work fine for a bit then gives me the "authorization failed" all over again. After this happening too many times I am giving up on K9. Maybe someday all this will be fixed and then I will give K9 another chance. Until then it no more.

  60. Frank Dillon-avatar

    Was great. Having problems with syncing, not receiving notifications. There have been several updates to Galaxy S10, maybe that is the cause.

  61. Chuck Boyle-avatar

    I have used this for several years and currently have it installed on my phone and Kindle with 9 email accounts all feeding into the unified inbox. Even though many reviews mention trouble with syncing, once you have all the settings cooperating with each other everything works just fine. My only complaint is that encrypted password is not supported.

  62. Erinç Dikici-avatar

    The app has nice customization options despite being an open source project, however it drains the battery of my device too fast. I would gladly wait for a fix, but unfortunately other users' requests on the same topic have recently been marked as "non actionable" by the lead developer, so it gives me no other option but to uninstall.

  63. Larry B-avatar

    I was using this app with (5) POP3 accounts for many years with no problems. Recently though, it started giving me the dreaded "syncing disabled" message and the network would no longer connect right away. To help prevent this, I deleted the POP3 accounts and recreated them using the IMAP protocol instead. Never had a problem again, and actually, IMAP can now "push" your message delivery instantly…smooth !!! Bye bye POP3 !!! Just make sure you leave your "Sync" feature enabled to allow the connection. I was leery of that as I thought it might use a lot of battery by keeping the sync feature enabled, but I monitored this for a while and to my surprise, it didn't. For example, my Galaxy S10e only uses about 10% of the battery in one entire day if no other apps are being used…not bad, huh? As a side note, I even tried using a few of the other recommended mail apps like BlueMail, but kept coming back to K-9, this despite the fact that it hasn't been updated since late 2018. I just like the interface and the features are plenty for me.

  64. Daryl Metzger-avatar

    Worked fine at first, but now requires 5 or 6 attempts before it will download mail from my servers. If I use it for sending, about 80% of the time I get a "failed to send some messages" notice. Happens both on wi-fi and 4G. I use it because it's apparently the only email client that works with Startmail with current Android OS on Galaxy S9.

  65. A Google user-avatar

    For anyone having issues with notifications, go into your settings, search for "Optimize Battery Usage", and DISABLE it for K-9 Mail. It's enabled by default and it causes Android to restrict its power usage (by putting it to sleep I assume?), and hence, not allowing any notifications to come through. Once I disabled it, K-9 was working perfectly. Love the app, would recommend to anyone looking for a FOSS mail app on Android.

  66. Kevin Donnelly-avatar

    Sadly, K-9 is no longer up to the task of it's main function. I've used it for many, many years but since Android 7 it's failed me regularly across three phones. Mostly this means it won't sync mail status nor deletions on some accounts. It will simply disable sync and not let it work again even after removing the account and re-adding. Removing and reinstalling the app shortly results in the same failure. It hasn't been updated in too long, so I put the blame there. Good bye, sweet K-9.

  67. Franck Kzoom2-avatar

    Everything you would need from an email client without any ads. External sd card support is sweet.

  68. Max Power-avatar

    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.

  69. John Brook-avatar

    It's a great open source app, but it hasn't been updated in a year, which means it is not staying on top of security issues. I would use FairEmail instead.

  70. Rocket Rod Lamont-avatar

    Rocket Rod Lamont


    Keeps stalling for hours especially when checking drafts folders. I have to force stop to end the failed checking of my email accounts. Using IMAP on Android 10..

  71. Matt Johnson-avatar

    Great app. I've been using it for years with my Yahoo email. Currently I'm having an issue where the App does not pull my emails even though I have it set for every 30 minutes. If I open the app it starts pulling emails. I'm on Samsung Note 8 running latest firmware. I would like a response from the developer.

  72. A Google user-avatar

    I don't hate this app, I spend almost 3 hours on how to set-up, I searched on the internet but it seems like I'm the only one having this problems. I follow the documentation but still won't work and try the default set-up but still no luck. I feel like I need to create my own IMAP server in order for me to use this app. IDK how much work needed to create my own IMAP server but I'm gonna try it. I rate it as one star because it is not a user friendly based on my experience, this is a great app. It open you to a deep technical knowledge if I'm right.

  73. Iron Spring-avatar

    This eMail app is open source and still under construction. Open Source is the way to go with any app like this for security reasons. It works great. It's a little different then most but there is plenty of documentation on GetHub. Super fast and highly configurable. I would not suggest this email app for a novice although basic configuration is documented and most of it is preconfigured. Just add your Gmail account and you should be ok. I however suggest you go to GetHub and read through the folder class information. Works super fast. Way faster and smaller then Gmail or your native email client. Once you get it working you can bloat stop Gmail and native. No stinking ads which you know that's not the case for others. Small in size over other email clients. Reliable and so configurable. Great job open source team. Still has some small growing pains but they are still working on it. Again I do not suggest it for a novice but it can be done. Ron @ Memphis, Tennessee USA

  74. Eric C-avatar

    can't send nor receive emails. gives error popup but to fast read.

  75. Matz erich-avatar

    * Good email app with some bugs. I use it every day. * 2019.05.03 Search is broken. Same results show up regardless of search keywords* Sometimes it hides unread emails in unified inbox for weeks and then, all of a sudden they show up again. * New bug: Forgets different email folders of my gmx mailbox. This results in showing up unread emails from that folders in unified inbox as if they were new. Refreshing folder list of affected email account does not help.

  76. A Google user-avatar

    Best free email app. I have recently come back to K9 after using a paid app. I was running out of storage so I reluctantly ditched A***mail for something less bloated. I reluctantly installed K9, remembering how buggy it was 3 or 4 years ago. Wow, what a surprise! Ok, it still doesn't look that great, but it's super fast and so far syncs reliably. And it's only 2.5 mb in size!

  77. A Google user-avatar

    ★Anyone desperately seeking the way to add additional accounts - tap the little < (lesser than) symbol next to the dog icon.★ This app is quite powerful, and it takes some getting used to - menus are context-sensitive and a little labyrinthine ;) Under IMAP, in the All Messages tab, "local" files can't be distinguished from those on the server - I accidentally cleared some files from my archive. It's best to use K-9 in conjuction with some webmail interface while getting your bearings.

  78. Ted and Jenny Davini-avatar

    Ted and Jenny Davini


    I've used this app for years but for about several months now my messages disappear after I have read them (they have not been deleted). sometimes they are the, sometimes they address not. I need to be able to continue to confidently see all messages in the inbox after they've been read. will have to look elsewhere...

  79. Robert Tickle-avatar

    I was a K-9 Mail user for years, but stopped using it when email notifications stopped working on my Galaxy S7. Recently, I tried K-9 mail again. The logo is very diffferent so I assumed there have been lots of improvements since I last used it. The new version of K-9 mail works great! Very configurable and the email notifications work perfectly on my Galaxy S9. K-9 mail still doesn't support two-factor authentication, but if you use an App password from Google it works great with Gmail.

  80. Josef H.-avatar

    Won't allow me to sign in, keeps saying my "user name or password is incorrect" when I know for a fact that it is correct.

  81. Dave Baron-avatar

    I like thie app, but I'm not sure how to report a bug. If you put multiple bccs on an outgoing message, and separate the addresses with semi-colons rather than commas, the message does not send when you press send, it stores to drafts. No error message, your message just doesnt get sent. Putting a comma fixes it. Seems a little harsh.

  82. Pinkie Vi-avatar

    Used this app for years but recently it stopped syncing. Despite background syncing is set to "Always on" it says "syncing disabled" or when kept open it counts down the minutes to the next sync but doesn't sync afterwards but instead says stuff like "next sync 1 minute ago" when the countdown would have hit negative numbers. This is true on both of my phones, sadly. I don't even know what to replace this app with - please fix it. :/

  83. Sarah J-avatar

    Eats huge data, inexplicably. I like the fact that you can see in the same view mail from different accounts and see which account they belong to, but it has gone on a data spree several times. The last one it "ate" almost 4GB in less than 2 days. It's inexplicable and unacceptable. I'm uninstalling.

  84. A Google user-avatar

    Got me beat! Spent hours trying to get this to work with an imap account. I could get each folder to download messages once, but the moment I would do a refresh, all messages disappear and no joy ever getting them to redisplay again. I suspect the sync mechanism is badly broken based on my Google research. Running on a Samsung Galaxy S8 FWIW

  85. A Google user-avatar

    Why is this app available on Google Play ??? I couldn't make the app function . Then, I realized that Google had notified me that they “recently prevented [me] from signing in to your Google Account” . Upon further investigation I had received a message: “Google blocked the app you were trying to use because it doesn't meet our security standards. Some apps and devices use less secure sign-in technology, which makes your account more vulnerable.” SORRY, I will not use this now!

  86. Jesse Duncan-avatar

    How the Mighty Have Fallen - used to be my go-to app for email on all my Android devices, but since I upgraded to an S8+, the app no longer syncs my mail. Checked the dev forums, this issue was reported but the devs closed the ticket as "will not fix," so the app is essentially useless to me now. Good job shooting yourselves in the foot.

  87. A Google user-avatar

    Despite some claims to the contrary, k-9 mail works fine with the basic hotmail and gmail accounts. You will initially get authentication and security messages due to IMAP but this can be quickly and permanently fixed by logging into your email accounts on a PC. the whole reason for me switching to K-9 was the capability to store email on an SD external memory card. My Samsung S5 only has 16gig internal and other email apps hogged 500megs. Voila, freed up internal memory for other stuff!!!

  88. A Google user-avatar

    Used it for years together with K@t Mail. Removed both of them in time because they lack consistency. In particular a) many times I don't get notifications when I receive work mail, which ended up with me losing countless jobs. B) often outbound messages won't go through, delaying answers, including the apologies for the missed mails. This made me lose a few good customers, too. Shifted to another product.

  89. Marty Rosenzweig-avatar

    Marty Rosenzweig


    ANDROID 10! Otherwise very good app. One issue is that a "starred" email appears at the top of the page as it should until it is older than the 100 or whatever number of emails to display. Then it disappears! If it was important enough to "star" it should remain at the top, regardless.

  90. John Bollinger-avatar

    This is a terrific email app. Set up was dead easy and everything works as expected. I saw some one star reviews claiming some functions don't work and suspect trolling as all functions tested fine for me. If you want a straight-forward email app that you can trust and that respects your privacy give K-9 a try.

  91. Elena Emblen-avatar

    Finally, an email app where you can set all font sizes! I can actually read the text in this one. If you are tired of ever changing fashionably cluttered looks and are not after fluff and glitter, then this is for you. The interface is very plain, but the way the message list is organised is fully customisable - title first, sender first, preview lines, split view, all font sizes, shading for read/unread, dark theme - even per message on the fly. Plus all the functionality, of course. 👍

  92. Albert A-avatar

    not a bad one in comparison to other apps, but: - notifications are sent randomly (you can have 10 new mails without any notifications) - UI has no logic (when you click on a mailbox you enter the "Inbox" folder; but when you click "Back" it does not bring you back, you rather end up in the list of folders

  93. Rick Acton-avatar

    Abandoned-ware. Back in the day, this app was the bomb. These days it seems it is no longer supported. Does not sync IMAP properly, does not handle security certificates well, does not fetch in the background, no notifications when mail arrives. Strictly bush-league now. I switched to Blue Mail and love it. Uninstalled.

  94. Beermeister General-avatar

    Beermeister General


    great solid email app with no ads, Ive been using it for around 2 years without a hitch nice work 👍

  95. Sheldon-avatar

    Best email client, even if it's not been in development for years it is still my go to email app

  96. Vladimir Milosevic-avatar

    Vladimir Milosevic


    I still use it after many years because it is the only app that can be customized to one-line message lists. I receive hundreds of mails daily and this is the only way for me to screen them fast. It is a great app altogether, free of silly gimmicks and straight to the point. Keep it up and thank you!

  97. Chris Bennett-avatar

    Thanks for the good times, K-9. I've really enjoyed this app over the years, but the time has come to finally admit that the lack of full HTML capability and other features is no longer acceptable. I've moved on to Blue email for now. If a fully revamped K-9 comes out in the future I'll give it a try.

  98. Fred Chapman-avatar

    I had a lot of problems using the Gmail app with IMAP accounts, so I tried this app instead. K-9 Mail works much better with IMAP. Unlike Gmail, this app provides immediate IMAP email notifications, can access the IMAP Drafts folder, and shows the correct subject line if the subject changes in the middle of an email thread. I wish K-9 Mail could collapse and expand the hierarchy of IMAP folders like Gmail does, but K-9 Mail doesn't even display the folder names in a readable way! My biggest problem with K-9 Mail is that the interface is just too bare bones. I switched to Edison Mail, which has a clean, beautiful interface that's a pleasure to use. Edison Mail is by far the best Android app I've found for IMAP.

  99. Pavel Larionov-avatar

    Push notifications are very unreliable. I can sometimes get notification for one account, but not for another, sometimes it works like it should, sometimes I am not getting notification at all. I double checked the settings, notifications are available everywhere.

  100. Michael Dismuke-avatar

    Michael Dismuke


    I really liked this app, but I removed it from my phone. This app stays in the phones memory and can not be moved to an external SD card. If they change it to make moving it an option. I would reinstall it. Because I had to delete it, I give it a 'Just OK' rating of 3 stars, otherwise it would have been maybe a 5.