K-9 Mail is not available for Linux but there are plenty of alternatives that runs on Linux with similar functionality. The best Linux alternative is Thunderbird, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to K-9 Mail and 12 are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to K-9 Mail are Betterbird, Evolution, Mailspring and Claws Mail.
Cross-platform email client supporting multiple identities, chat, and strong filtering. Extend functionality with add-ons like RSS/Atom feed readers and PGP support.
United States
Betterbird, a soft fork of Mozilla Thunderbird, improves user experience with advanced features, bug fixes, security patches, and multi-row descriptions similar to Outlook. Compatible with multiple platforms and can be used alongside Thunderbird, sharing the same profile.
Germany
EU
Evolution is a personal information management application that provides integrated mail, calendaring, address book and task list functionality.
United States
Boost your productivity and send better email with Mailspring, a beautiful, fast email client for Mac, Windows, and Linux. Mailspring is free to use and an optional pro version adds read receipts, send later, reminders and more.
United States
Email and news client on GTK+ foundation featuring quick performance, extensible plugins, secure protocols, advanced filtering, strong folder and contact management, lightweight design, powerful search, customizable interface, multi-language support, and encryption.
BlueMail is a modern, mobile first, powerful Email management tool with a sleek design, unified inbox and support for all your accounts: IMAP,Exchange,POP3.
United States
TypeApp is an all-free, beautifully designed, universal email app, capable of managing unlimited number of mail accounts from various providers, allowing for smart push notifications while enabling personalization across multiple email accounts.
United States
Japan
Nylas Mail Lives is a fork of Nylas Mail that fixes many longstanding issues, improves the client experience, and is committed to publish new releases.
Columba is an email client written in Java, featuring a user-friendly graphical interface with wizards and internalionalization support. Its a powerful mail management tool with features to enhance your productivity and communication.
Built from the ground up for speed. Flectar Mail delivers native performance, instant startup, and as little as 20 MB of RAM.
SpainEU
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.
United States
