K-9 Mail APK

Version 5.725 - com.fsck.k9
Last updated: Thu, 19 Nov 2020 14:33:34 UTC

K-9 Mail apk

APP Information

Download Version 5.725 (27025)
Apk Size6.56 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 5.725 APK

App Description

K-9 Mail is fsck,communication,mail, content rating is Everyone (PEGI-3). This app is rated 4.29 by 41 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 5.725 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 195861+ 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 

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. John K-avatar

    John K


    Please fix the long-existing problem where the new mail notification usually disappears on its own (sometimes after just a couple of seconds, and sometimes after a number of minutes). I don't have the problem with any other app, and I am often failing to see emails on time because of this. Many people are experiencing this and have complained.

  2. Joseph Bolanos-avatar

    Joseph Bolanos


    Sends emails to DRAFTS, Not Out. Worked fine at first, but has a glitch where emails are sent to DRAFTS OR TRASH when you click on SEND arrow. Really disrupts business. Last update was 2 years ago so it's probably flawed and developer has folded. This app should no longer be in the app store. Will advise Google store.

  3. Tim Lewcock-avatar

    Tim Lewcock


    Excellent app which has survived multiple device changes. Great features and allows you to use multiple email accounts from a variety of email providers. The only criticism I have (thus dropping one star) is that I haven't figured out the settings to use to ensure the App is operating at Google's recommended security level; Google's gmail warns the App isn't as secure as Google would like, so you have to enable the account for using less secure access, but that's all and it's working for me.

  4. DanielTheGreatAu-avatar



    I probably gave this a 5-star review when I first started using it several years ago. Used it on every phone since, but on my latest phone (UmiDigi A7 Pro with Android 10) it no longer fetches mail in the background. Sadly, it appears to have been abandoned and no longer keeping up with the times, so I've had to switch to FairEmail.

  5. Struktur AG-avatar

    Struktur AG


    After a year or so, fetching email isn't properly working any more and properly half of the emails aren't shown any more. Happened multiple times in the past years. Only deleting email and re-installing the app solved the problem.

  6. MS MS-avatar

    MS MS


    Gmail has been increasingly blocking this app as unsecure for a year. It's to the point now where syncing is completely disabled, despite my going to each email account's settings to enable "Use less secure apps". Apparently, it's not been updated since 2018, so sadly it's time to find a functional multi- email app. It was good while it lasted. Thanks for the alternate suggestions everyone.

  7. Serguei Patchkovskii-avatar

    Serguei Patchkovskii


    The perfect e-mail client. Fully functional support for multiple accounts and IMAP folders. Also includes the ability to examine message headers, which is invaluable in triaging potentially-malicious messages.

  8. Logan Rathbone-avatar

    Logan Rathbone


    Editing my review. It is still 5 stars due to the legacy of it being one of the best Android email apps for a decade, but I would now only recommend on legacy platforms. IMAP IDLE does not work well anymore since Doze and they have now cut IDLE support from their GitHub trunk. New mail notifications are unreliable as a result. I would recommend FairEmail as a good replacement for newer platforms.

  9. Matthew Perlman-avatar

    Matthew Perlman


    I have been using this for many years. One feature I would like too see added however is the ability to disable the scroll bar. I keep hitting it accidentally, and it sends me way down to the bottom of the list.

  10. Ranjit Kour-avatar

    Ranjit Kour


    An Excellent Email Client. Sync completely well with my google account and no delay in recieving and sending Emails. App size is also quite small which makes it perfect for even low power devices. 100% Recommended.

  11. Setnakt Spears-avatar

    Setnakt Spears


    Completely useless. Doesn't recognize passwords anymore making it completely useless. When you first open the app you get a message saying that this was designed for an older version of Android, look for an update. Perhaps if the developer would update the app it would work again?

  12. pisco kid-avatar

    pisco kid


    I have just switched from Bluemail, and am suddenly gettiing a lot more spam, every 10 minutes now as opposed to 2 or 3 a day. Unable to block spam domains with this app.

  13. Michael Phillips-avatar

    Michael Phillips


    Total BS app. Will not allow me to sign in, keeps telling me that my email address or password are wrong. I know what my email address and password are. Uninstalled. Update : checked my email, and found an email from Google saying that my sign-in to this was blocked by Google for being unsecure. Why this is even on the Google Play store is baffling.

  14. Shiva Baba-avatar

    Shiva Baba


    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.

  15. Cyber Pen2k-avatar

    Cyber Pen2k


    It's a great app with a small footprint no adds and great features. Everything works except push notifications. So I use Gmail app to give push notifications for my email and k9 for everything else. This would be a killer app otherwise. Thank goodness it still works!

  16. Beej-A Koupps-avatar

    Beej-A Koupps


    best interface of any client :) html support is very behind, especially when it comes to signatures. deciding which folders to sync when and how often is configurable somewhat, but difficult, even with the docs. otherwise it's great!

  17. Gus Laursen-avatar

    Gus Laursen


    It works... Kinda. Like others have reported, I also experienced issues with it fetching my emails without me having to force a refresh. I used this as my business email client on my phone - big mistake. I missed a couple of leads before I realized it wasn't even updating at all. I went over all my settings and there was no reason for it not to be fetching my emails. I switched over to Blue Mail and it has had no problems syncing my email.

  18. Sasha Price-avatar

    Sasha Price


    Ended up deleting. I loved this app and was using it for years but there is just no support for bugs and the last update was over a year ago. Emails constantly sitting in outbox and not sending.

  19. Richard Booty-avatar

    Richard Booty


    Settings make no sense. Emails have randomly started moving to bottom of list. After many hours in the settings I've given up and deleted the app. Battery consumption is horrific.

  20. Agent Black-avatar

    Agent Black


    Dumping K9. This app was the bomb back in the day when it actually worked. This "syncing disabled" problem is too much. No support anymore either. Too bad. On blue mail now, & it seems to work so far....

  21. Gregory M-avatar

    Gregory M


    Difficult to navigate settings. Difficult to understand what "first class", "second class", etc.. what is a class? Difficult to locate a specific setting. There is global settings, I understand. But each account has it's own settings, ok too. But there should be a way to change all accounts with one setting. For example, to sync sent folders, I want them all changed, I don't want to go into each of my 13 accounts and change them one at a time. Navigating endless pages of settings is hard.

  22. Michał Trojnara-avatar

    Michał Trojnara


    I had to use K9 for many years due to lack of a better alternative (PGP support is an essential feature to me). The configuration is terribly bloated and it took countless hours of tinkering to get it right. K9 seems no longer actively developed (no new releases since 2018). I'm glad I found FairEmail and I could get rid of K9.

  23. Lalit Kumar Barik-avatar

    Lalit Kumar Barik


    Since today morning (October 01, 2020) I am getting "Sync Disabled" message while syncing. New mails are not being shown.

  24. W. Barcikowski-avatar

    W. Barcikowski


    Excellent replacement for stock telco/android email app which started to have problems sending emails. Light, fast, dark mode and with options under the hood (modern synching options + more). [GMail is good as r many others but need seperate app for things that r my personal stuff.] Have been using 4 a month and pleased with performance. Looking forward to the updated version when available (check out developement site on github). Thanks to all the contributors who worked on this app.

  25. Maarten de Jong-avatar

    Maarten de Jong


    Best Android email client out there. Background sync and notifications don't seem to work well. I always have to refresh manually.

  26. Dave Sales-avatar

    Dave Sales


    Generally works well I have had to uninstall and reinstall two or more times in the past few weeks. It would go on abd off instantly. No error message.

  27. Sof Gdggd-avatar

    Sof Gdggd


    Does pretty much everything you'd want in a mobile email client. A nice feature is saving a draft as soon as you have to switch to another app.

  28. Chris Mailloux-avatar

    Chris Mailloux


    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.

  29. Gilbert Hamilton-avatar

    Gilbert Hamilton


    I have been using this app for several years and until recently it has been a great app. Now, it fails to check for mail at any time interval you set it to. I need to force a manual refresh to get mail which is useless. I'm now looking for an alternative that works.

  30. Lou S-avatar

    Lou S


    Love k9, have used for years, but Gmail stopped working because it no longer will accept my passwords, even registered as an"insecure app", wants oauth2. Guess I need to try the beta version (didn't want to be bleeding edge with my daily email app). If no oauth2 support, I will be forced to change.

  31. Stephen DePaoli-avatar

    Stephen DePaoli


    Useless on Android Everything has to be done manually just to see new messages. Used to work well but now it's of no value.

  32. Rui Martins-avatar

    Rui Martins


    Been using this app for years, tried one and another once in a while, but even not being perfect, I always end up electing k9 as my daily email app. The biggest lack, in my opinion, is not being able to deal with the most actual exchange server definitions

  33. Jim Fox-avatar

    Jim Fox


    For those saying this has been abandoned, it hasn't. Go to github and download the latest version. It IS still in active development! It will eventually show up here. Be patient!

  34. Grimlance Deathknell-avatar

    Grimlance Deathknell


    Immediately started receiving new spam on a very restricted and complicated spam filter. Coincidence? Not likely.

  35. Super Mario-avatar

    Super Mario


    A phenomenal app - in terms of both functionality and UX. Thank you!

  36. R N-avatar

    R N


    It has some good elements and it's very responsive but unfortunately it is effectively abandoned. They're saying it's not but it hasn't been updated since 2018. I was forced to switch to a different app.

  37. Mikey Kuplevatsky-avatar

    Mikey Kuplevatsky


    Yikes, this is a blast from the stone age. It hasn't received any updates since 2018 and also the UI looks like it's from the 80s. Or more accurately, from Android KitKat era. The devs probably don't care, but oh well. Well on their way out anyway, less consumers. On the flip side, it was an enjoyable experience many years ago but it's outdated and irrelevant now.

  38. Jez Hopkins-avatar

    Jez Hopkins


    "Authentication failed. Please update password." Every phone I've used K9 Mail on has had this error. My password does not need updating and it has not changed. I want to like K9 but this is a recurring bug with no solution online so I have no choice but to use something else. Shame

  39. Derek Jones-avatar

    Derek Jones


    I like this app it works well and does what it's supposed to. It could do with an update not in functionality, as it does what it's supposed to, but it could do with a tidy up and a face lift

  40. Vojko Vašl-avatar

    Vojko Vašl


    After testing many e-mail clients for Android k-9 is definitely the best solution. Has clear simple friendly interface, works smoth and fast. I use it for 5 email addresses. There are no annoying ads and the program is free. What do you need more in this matter?

  41. Kamaljeet Singh-avatar

    Kamaljeet Singh


    Had a very nice and easy experience using K9 mail. The developers of the app have done a very commendable work. Lot of scope for improvement.

  42. Behrouz Mohammadzadegan-avatar

    Behrouz Mohammadzadegan


    Great app and I have been using it since galaxy s2 but lately it has started giving me errors and shuts the app down and doesn't do the job it usually does. Is there a new update coming up for it? Or is this problem going to stay?

  43. Rich Harle-avatar

    Rich Harle


    Good but not great - had most functionality you'd expect from an email app, but some odd bugs: Will sometimes popup that there's an email and the notification vanishes instantly Can't relocate items once deleted (so if accidentally deleted or moved to junk, unable to move back to inbox)

  44. Private Information-avatar

    Private Information


    Needs an update!! You can't send an E-mail if you switch to another app while it's sending (the connection breaks). Otherwise, good app. Like the "1st\2nd" level folder options especially.

  45. Rudolph Yustian-avatar

    Rudolph Yustian


    Used this app quite a lot, recently kept telling me that this app may not work properly because it was made for older version of android, then direct me to google play only to find latest release already installed. Hasn't been able to sync since then.

  46. Joseph YG Kamal-avatar

    Joseph YG Kamal


    Very reliable & stable mail for android. Iam using this for the past 4 years with out any issues.

  47. Ruth Morris-avatar

    Ruth Morris


    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.

  48. Peter Snow-avatar

    Peter Snow


    Excellent. Nice to finally have some guaranteed privacy. Works nicely with multiple accounts.

  49. ______-avatar



    Great mail app, but the latest version has intrusive pop up notifications every time it checks for new mail which can get in the way of things. A minor issue though, I really like the configurablility and interface.

  50. Jesse Black-avatar

    Jesse Black


    Old but good and works well and low resource. Love that i can switch storage to sd card. Love that spam filter is free. The best ! Maildroid wont even let me do this and i paid for it. Update : defaulted my phone and issue is fixed.

  51. CG-avatar



    Will not fetch mail at set interval. Disappointed, will look for another. Needs to be updated to fix this or it is a useless app. Tried it on 2 different phones with the same problem. Will be uninstalling until fixed.

  52. Rhonda Thompson-avatar

    Rhonda Thompson


    Have used this app for years and it's by far the best. When it works. It constantly (several times a day) freezes while polling gmail accounts. It is not the gmail account, I've tried a few.

  53. Mike McCord-avatar

    Mike McCord


    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+.

  54. Euclid Megara-avatar

    Euclid Megara


    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.

  55. Michael Rupp-avatar

    Michael Rupp


    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!

  56. B. W.-avatar

    B. W.


    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.

  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. Larry B-avatar

    Larry B


    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.

  59. caue rego-avatar

    caue rego


    it would be awesome if it was updated... still looking for a good alternative. perhaps newton or bluemail...

  60. 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.

  61. Chuck Ray-avatar

    Chuck Ray


    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!

  62. Kevin Donnelly-avatar

    Kevin Donnelly


    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.

  63. St St-avatar

    St St


    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.

  64. Bill Harvey-avatar

    Bill Harvey


    Have used this app for years, but since Android 10, it fails to fetch emails when it's supposed to. If this continues, I'll be forced to find a new email app.

  65. Michael Fox-avatar

    Michael Fox


    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.

  66. I am ion's Cat-avatar

    I am ion's Cat


    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.

  67. Max Power-avatar

    Max Power


    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.

  68. Iron Spring-avatar

    Iron Spring


    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

  69. T Schilling-avatar

    T Schilling


    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).

  70. A Google user-avatar

    A Google user


    Update 05/25/2020: Still my go-to email app. Works reliably and intuitively for me. The easiest to use and the best features of all the many apps of its type that I've tried! 😃👍❕👌😎

  71. A Google user-avatar

    A Google user


    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.

  72. A Google user-avatar

    A Google user


    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!

  73. Neil Hallam-avatar

    Neil Hallam


    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.

  74. Matz erich-avatar

    Matz erich


    * 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.

  75. Robert Tickle-avatar

    Robert Tickle


    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.

  76. 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...

  77. Stephen Prentice-avatar

    Stephen Prentice


    The arrogant and unapologetic devs have killed a once great email app. If you have several email accounts, this app isn't for you because they have "upgraded" the app and removed the global account view. K-9 UI/UX is no different than Gmail now.

  78. Noah Mendelsohn-avatar

    Noah Mendelsohn


    A terrific and flexible email app with no advertising etc. Does both pop and.imap.

  79. Pinkie Vi-avatar

    Pinkie Vi


    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. :/

  80. Yasser Sedky-avatar

    Yasser Sedky


    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.

  81. John Brook-avatar

    John Brook


    It was 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.

  82. 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.

  83. Dave Baron-avatar

    Dave Baron


    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.

  84. A Google user-avatar

    A Google user


    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.

  85. Sarah J-avatar

    Sarah J


    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.

  86. Moto Max-avatar

    Moto Max


    Do not waste your time with this piece of junk. It regularly crashes and you lose all your emails from a bug that has been around for a couple of years now. Find something better!

  87. Robert P-avatar

    Robert P


    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.

  88. Jesse Duncan-avatar

    Jesse Duncan


    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.

  89. Malte Esders-avatar

    Malte Esders


    Has all features a modern email client needs. And I heard there's a big update with a user interface overhaul on the way, too!

  90. A Google user-avatar

    A Google user


    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!!!

  91. 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.

  92. A Google user-avatar

    A Google user


    Used it for years together with [email protected] 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.

  93. Erinç Dikici-avatar

    Erinç Dikici


    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.

  94. Chuck Boyle-avatar

    Chuck Boyle


    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.

  95. Daryl Metzger-avatar

    Daryl Metzger


    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.

  96. Albert A-avatar

    Albert A


    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

  97. Jo-avatar



    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!

  98. Elena Emblen-avatar

    Elena Emblen


    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. 👍

  99. Rick Acton-avatar

    Rick Acton


    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.

  100. 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).

  101. 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!

  102. A Google user-avatar

    A Google user


    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.

  103. Rota Brūna-avatar

    Rota Brūna


    This is so much more than a simple email app. It is highly customisable, easy to use and with a good dark mode. The best email app out there.

  104. Fred Chapman-avatar

    Fred Chapman


    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.

  105. 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.

  106. Matt Johnson-avatar

    Matt Johnson


    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.

  107. Bptec One-avatar

    Bptec One


    After using the app for sometime I have had to delete it. The app is not reliable at all. I constantly have draft emails that just delete and cannot be used once they are in the trash. The app seems to generate lots of duplicate emails as well. The other issue is that it is really just unreliable as a critical app.

  108. Asswipe Holio-avatar

    Asswipe Holio


    Used this app for years, but i'm going to install it and use another app. Why? Because it says "syncing disabled" for most of the time so no mail is being retrieved automatically. Apparently they are not doing anything to fix this. A shame for such nice application as it used to be.

  109. Glenn Reffin-avatar

    Glenn Reffin


    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.

  110. A Google user-avatar

    A Google user


    ★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.

  111. Pixy Stix-avatar

    Pixy Stix


    I never thought there could be a mail app that would pull me away from Outlook. I was wrong. I love this app. It's simple, intuitive, non-cluttered, and even allows PGP encryption for those private moments that you want to stay private. 100% recommend! Give it a try!

  112. Ralph Stele-avatar

    Ralph Stele


    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.

  113. Scary Barry-avatar

    Scary Barry


    Was working great for over 1yr. Now it is crashing every time I open it. My main biz email I can't even get the polling on sent items. Now I have wasted so much time on it I have gone mad. No settings change. Same from the beginning. Uninstalling now. And maybe retry.

  114. the Mule-avatar

    the Mule


    Runs in the background after closing, wasting battery and data

  115. Caps CC-avatar

    Caps CC


    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.

  116. No Thereisn't-avatar

    No Thereisn't


    Possibly the best email app, or at least has everything I need for my IMAP4 accounts. Perhaps Gmail users think differently but I'm staying loyal. Just 2 flaws: 1) sometimes gets stuck on syncing, 2) BRING THE OLD 3D ICON BACK! I hate the current trend of infantile, simple flat icons with no character.

  117. Charlie Whiskey-avatar

    Charlie Whiskey


    Was a great app for years and I recommended it to many folks. However, it has intermittently stopped syncing email on my last few devices. Dug into dev forums to resolve, but nothing appears to work to correct the issue. Moving on to an email app that, well, receives email.

  118. Martin Halva-avatar

    Martin Halva


    It is astounding but probably not for everyone. If you want to learn how to use it and set it up, then you get an really powerful email client. The level of possible customization is amazing. And K9 allows you to use the pgp cryptography as well (sign and crypt emails).

  119. Michael Spiegel-avatar

    Michael Spiegel


    Used to be good. After many updates all the good parts are gone. No longer getting notifications. No longer actually checking my mail, I have to manually sync it just to see if anything shoes up. Not happy with this anymore.

  120. A Google user-avatar

    A Google user


    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!

  121. Gary M-avatar

    Gary M


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

  122. Stiofan MG-avatar

    Stiofan MG


    Love it! Simple, straightforward, no gimmicks. Just does what it says on the tin.

  123. A Google user-avatar

    A Google user


    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

  124. Juancarlos Hernandez-avatar

    Juancarlos Hernandez


    Unique option for users who wants to use encryption options, just it would be great if you add an option to lock the app, ao anitjer one who don't know the pass or the pattern can't unlock it.

  125. Jake Gutteridge-avatar

    Jake Gutteridge


    It's a fantastic email client with no ads, an easy-to-use interface and lots of features.

  126. Яков Н.-avatar

    Яков Н.


    Amazing app! Old school in desgin but MUCH more functional than other. I loved its Searching capabilities - it actually can search your old emails in the server WITHOUT downloading (fetching) all emails. I wish I could donate to this project in future, very impressed! THANKS A LOT!👍

  127. R Howard-avatar

    R Howard


    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.

  128. A Google User-avatar

    A Google User


    Call me naive, but I want apps that have a great GUI, are free from ads and work correctly. K-9 Mail wins on the latter two wants but has a very plain GUI. That said, its the best multi-account app in the store, and of course, it's free. Good work guys. Thank you.

  129. Axel Hellström-avatar

    Axel Hellström


    Bland design, missing several key features like retrieving mail from the trash too. Cmon guys, it's 2018 I've seen Netscape mail in the 90s let you drag messages from folder to folder. News flash: Account type has nothing to do with moving local messages. Stop being lazy and stubborn and enable it on POP accounts already.

  130. SAM H-avatar

    SAM H


    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?

  131. Martin Neumann-avatar

    Martin Neumann


    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.

  132. John Bollinger-avatar

    John Bollinger


    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.

  133. Sjaak van Rutten-avatar

    Sjaak van Rutten


    Been using this for my IMAP mail for years now, and it does exactly what I want an email app to do without extra fuzz. Love it!

  134. Maddy DS-avatar

    Maddy DS


    Works well, but ugly. Should have option to display list of folders along with mail.

  135. Gordon Allen-avatar

    Gordon Allen


    Does NOT deliver POP3 nor iMAP email within any reasonable time frame. Many hours go by and my emails are not delivered to my smartphone, until I open the K-9 app and pull down on the screen from within inbox or click on the refresh button at bottom middle of screen. I've spoken with my ISP which also manages my email server, and they have no answers. YAHOO WORKS VERY FAST ALWAYS, but I don't want a yahoo email address for my business. I've selected EVERY POSSIBLE option under SETTINGS_ACCOUNT SETTINGS and SETTINGS_GLOBAL SETTINGS My smartphone is a Motorola Turbo2 Android with the latest updates AND I RESET TO FACTORY SETTINGS last week, including adding a 128GB SD Card for extra space. The phone itself has 32GB, and the used space so far is 12 GB (8GB.for the system files). I've complained for years, but no solutions have become available. Switching to another app soon. Blah blah blah.

  136. A Google user-avatar

    A Google user


    So far, very good: I came to K-9 after exasperation with MyMail and TypeApp both of which fail to implement the IMAP protocol properly (MM has no manual IMAP setting and TA refuses to use IMAP for OL365). Not the prettiest but K9 DOES implement IMAP properly (like Thunderbird). Well done chaps :)

  137. Swiss Tony-avatar

    Swiss Tony


    Worked perfectly for a while, now synchronising is disabled all the time. Sometimes you can manually sync, other times it fails. Hopefully the developer will address this issue as I want to keep using it.

  138. Alius S-avatar

    Alius S


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

  139. A Google user-avatar

    A Google user


    I was using paid Maildroid for some time, then it started failing license lookups and playing ads so I switched and K9 is awesome!!! Community built and supported, a full featured email client with no downside for me. Thank you to all the people involved

  140. Pavel-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.

  141. Chris Bennett-avatar

    Chris Bennett


    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.

  142. John F-avatar

    John F


    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.

  143. Eric Vey-avatar

    Eric Vey


    Using a Note 4 running 6.0.1 and the latest version of K9, there are no notifications of new messages. I had to uninstall the current version and install an older version (5.403) to have functioning email. To keep from accidentally updating it, I had to extract and sign the older version.

  144. Richard Whitehouse-avatar

    Richard Whitehouse


    Disappointed with the inadequate authentication security. Google blocked my login attempts while initializing the app and sent me a Critical Security alert. Since this is an ads-free app, I'd be very interested in trying it again if the developer(s) bring the authentication security up to Google's standards. Giving it only one star because I cannot even evaluate it with it this way.

  145. István Szekeres-avatar

    István Szekeres


    This has been my only email client on my phones for several years. Easy to set up. Does everything right. Never missed a mail.

  146. first name-avatar

    first name


    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.

  147. Ike Bottema-avatar

    Ike Bottema


    Wow! Tried several Android email applications and they can't match this one for just basic email services without all the distractions and especially security concerns with respect to granting access to all sorts of personal information!

  148. Dave Brown-avatar

    Dave Brown


    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).

  149. Erik Kowal-avatar

    Erik Kowal


    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.

  150. Wayne Louie-avatar

    Wayne Louie


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