K-9 Mail AlternativesOnly apps categorised as Contact Managers

Alternatives list

1. 

   

   Thunderbird

    2639 likes

   Cross-platform email client supporting multiple identities, chat, and strong filtering. Extend functionality with add-ons like RSS/Atom feed readers and PGP support.

   102 Thunderbird alternatives

   Cost / License

   • Free
   • Open Source (MPL-2.0)

   Application typeApplication types

   • Email Client
   • Calendar

   Origin

   • United States

   Platforms

   • Windows
   • Linux
   • Android
   • BSD
   • AppImageHub
   • Snapcraft
   • Flathub
   • PortableApps.com
   • F-Droid
   • OpenAPK
   • Homebrew
   • Chocolatey
   • Obtainium

   • United States

   

   

   

   +7

   

   More about Thunderbird  

   

   Good alternative?Is Thunderbird a good alternative to K-9 Mail?

    

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   2comments

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   Thunderbird vs K-9 Mail Comments

   Positive comment by Tubby 9417 · Oct 11, 2023

   A really great client used by many, popular because it supports almost every mail provider (not proton ?), and mail providers provide documentation to integrate with Thunderbird. I recommand

   Comment by Diatomee · Dec 13, 2025

   Afaik the Thunderbird for Android and K-9 mail are developed by the same team now and have the same infrastructure under the hood, therefore it doesn't make any difference which one you choose.

   2 of 2 comments

   

   

   • Thunderbird is Free and Open SourceK-9 Mail is also Free and Open Source
   • Thunderbird is CustomizableK-9 Mail is not according to our users
2. 

   

   Evolution

    212 likes

   Evolution is a personal information management application that provides integrated mail, calendaring, address book and task list functionality.

   77 Evolution alternatives

   Cost / License

   • Free
   • Open Source (LGPL-2.1)

   Application typeApplication types

   • Email Client
   • Calendar

   Origin

   • United States

   Platforms

   • Linux
   • BSD
   • Flathub
   • S/MIME
   • GNOME
   • OpenPGP

   • United States

   

   

   

   +4

   

   More about Evolution  

   

   Good alternative?Is Evolution a good alternative to K-9 Mail?

    
4. 

   

   Infomaniak kMail

    52 likes

   Privacy-focused Swiss email system provides 20 GB free storage, supports custom domains and unlimited storage, syncs contacts and calendars, is ad-free, and is part of a secure productivity suite used by over a million users across Europe on all devices.

   Cost / License

   • Freemium
   • Open Source (GPL-3.0)

   Application typeApplication types

   • WebMail Provider
   • Email Client

   Origin

   • Switzerland

   Platforms

   • Online
   • Android
   • iPhone
   • Android Tablet
   • iPad
   • F-Droid

   • Switzerland

   

   

   

   +8

   

   More about Infomaniak kMail  

   

   Good alternative?Is Infomaniak kMail a good alternative to K-9 Mail?

    

   |

   1comment

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   Infomaniak kMail vs K-9 Mail Comments

   Negative comment by Guest · Jul 21, 2024

   The Infomaniak client only works with Infomaniak mail accounts, while K-9 Mail supports all mail accounts that use the standard IMAP and SMTP protocols

   1 of 1 comments

   

   

   • Infomaniak kMail is Freemium and Open SourceK-9 Mail is Free and Open Source
   • Infomaniak kMail is a WebMail Provider K-9 Mail is an Email Client
5. Ad

   

   

   Infomaniak kMail

   Privacy-focused Swiss email system provides 20 GB free storage, supports custom domains and unlimited storage, syncs contacts and calendars, is ad-free, and is part of a secure productivity suite used by over a million users acro...

   https://www.infomaniak.com

   Learn More
6. 

   

   Flectar Mail

    4 likes

   Built from the ground up for speed. Flectar Mail delivers native performance, instant startup, and as little as 20 MB of RAM.

   Cost / License

   • Free
   • Open Source (AGPL-3.0)

   Application typeApplication types

   • Email Client
   • Calendar

   Origin

   • Spain
   • EU

   Platforms

   • Mac
   • Windows
   • Linux

   • Spain
   • EU

   

   

   

   +9

   

   More about Flectar Mail  

   

   Good alternative?Is Flectar Mail a good alternative to K-9 Mail?

    
7. 

   

   Koma-Mail

    4 likes

   Koma-Mail is an email client which is comfortable and has very handy functions. It does not need an installation, so that you can run Koma-Mail from your flash drive but, of course, also on your desktop.

   68 Koma-Mail alternatives

   Cost / License

   • Free
   • Proprietary

   Application typeApplication types

   • Email Client
   • Calendar

   Origin

   • Germany
   • EU

   Alerts

   • Discontinued

   Platforms

   • Windows

   • Germany
   • EU

   

   

   

   +7

   

   More about Koma-Mail  

   

   Good alternative?Is Koma-Mail a good alternative to K-9 Mail?

    
9. 

   

   Hylki

    Like

   Hylki is a fast, GNOME-native email client with a three-pane layout, unified inbox, and support for OAuth accounts. Fast to open, effortless to read, and private by default.

   Cost / License

   • Free
   • Open Source (AGPL-3.0)

   Application type

   • Email Client

   Origin

   • United States

   Platforms

   • Linux
   • Flatpak

   • United States

   

   More about Hylki  

   

   Good alternative?Is Hylki a good alternative to K-9 Mail?