Open Source Thunderbird Alternatives for Linux

There are many alternatives to Thunderbird for Linux if you are looking for a replacement. The best open source Linux alternative is Claws Mail. If that doesn't suit you, our users have ranked more than 50 alternatives to Thunderbird and many of them are open source and available for Linux so hopefully you can find a suitable replacement. Other interesting open source Linux alternatives to Thunderbird are Evolution, Betterbird, SeaMonkey and Geary.

More about Thunderbird
Copy a direct link to this comment to your clipboard
Thunderbird alternatives page was last updated

Alternatives list

  1. Claws Mail icon

    Claws Mail

     105 likes

    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.

    Cost / License

    • Free
    • Open Source

    Application types

    Platforms

    • Windows
    • Linux
    • BSD
    The main window
     
    |
    9
    Claws Mail vs Thunderbird Comments
    Top Positive Comment
    Jonathan Dumont
    9

    Despite the style, Claws is super fast and allow you to programs it with Perl and Python which is great for marketing automation.

    Top Negative Comment
    Guest
    22

    No HTML compose is the only reason I don't switch to it. We're not in 1980 anymore.

    Sam Lander
    Positive
    0

    Much faster than Thunderbird. It can be harder to set up for some institutional emails though.

    3 of 9 comments
    • Claws Mail is Free and Open SourceThunderbird is also Free and Open Source
    • Claws Mail is LightweightThunderbird is not according to our users
  2. Evolution icon

    Evolution

     212 likes

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

    74 Evolution alternatives

    Cost / License

    Application types

    Platforms

    • Linux
    • BSD
    • Flathub
    • S/MIME
    • GNOME
    • OpenPGP
    Mail
     
    |
    5
    Evolution vs Thunderbird Comments
    Top Positive Comment
    Michel Th.
    1

    I use both Thunderbird and Evolution, sometimes Claws-Mail. Evolution is the only one that can show the real "received" date in scams I have been receiving for months. In a today's scam Evolution shows "sent date" (falsified) 14-12-2019 and "received date" 30-01-2023 (evidently true). Thunderbird and Claws-Mail show 14-12-2019 in both columns.

    RemovedUser
    Positive
    0

    As someone who is forced to use M365 at work (but ditching it at home, I let my subscription lapse) this is the closest visually to Outlook. That's important to me. The workflow is essentially identical.

    Syntevo GmbH
    1

    Unfortunately, only available on Linux, not on Windows, not on MacOS. Otherwise promising.

    3 of 5 comments
    • Evolution is Free and Open SourceThunderbird is also Free and Open Source
  4. Betterbird icon

    Betterbird

     88 likes

    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.

    37 Betterbird alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Mac
    • Windows
    • Linux
    • Flathub
    • Chocolatey
    Betterbird screenshot 1
     
    |
    6
    Betterbird vs Thunderbird Comments
    Top Positive Comment
    Sam Lander
    3

    Betterbird does everything that Thunderbird does (it's a soft fork), while improving bugs and features.

    Because it's a soft fork, it retains the security implementations of Thunderbird.

    Thunderbird actually implements many of the bug fixes created by Betterbird, but at a much slower pace.

    Shoji VR
    Positive
    2

    has more features than thunderbird

    drummer_nrg
    Positive
    1

    Betterbird is actively updated by a previous Thunderbird developer and is a fully compatible fork of Thunderbird which fixes some outstanding bugs. My add-ons like keepassxc-mail work fine!

    3 of 6 comments
    • Betterbird is Free and Open SourceThunderbird is also Free and Open Source
    • Betterbird is LightweightThunderbird is not according to our users
  5. SeaMonkey icon

    SeaMonkey

     250 likes

    Web-browser, advanced e-mail, newsgroup and feed client, IRC chat, and HTML editing in one application. Itis built on the open source Mozilla Gecko engine, the same code which underlies Thunderbird and is the base for the Firefox browser.

    193 SeaMonkey alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Mac
    • Windows
    • Linux
    • BSD
    • PortableApps.com
    SeaMonkey screenshot 1
     
    |
    4
    SeaMonkey vs Thunderbird Comments
    Guest
    Positive
    21

    SeaMonkey is both a WEB BROWSER and EMAIL CLIENT. It's the successor of Mozilla Application Suite or Netscape Communicator, resp. Further it includes also a news client program, an HTML editor (SeaMonkey Composer) and an IRC client (ChatZilla).

    apostolfaliagas
    Positive
    15

    It has all of Thunderbird's features and many more.

    Guest
    Negative
    0

    Unfortunately doesn't support synchronization with CardDAV address books.

    3 of 4 comments
    • SeaMonkey is Free and Open SourceThunderbird is also Free and Open Source
    • SeaMonkey is a Web Browser Thunderbird is an Email Client
    • SeaMonkey is LightweightThunderbird is not according to our users
  7. Geary icon

    Geary

     110 likes

    Geary is an email application built around conversations, for the GNOME 3 desktop.

    50 Geary alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Linux
    • BSD
    • Flathub
    • GNOME
    • Flatpak
    • Linux Mobile
    Main window
     
    |
    4
    Geary vs Thunderbird Comments
    Kelson V
    Positive
    0

    Geary is a lot lighter than Thunderbird, so it's a good choice on lower-end hardware. IMAP features are basic, but 90% of what most people will need. It relies on GNOME for contacts, but the mail app itself can run on any Linux desktop.

    Guest
    Negative
    1

    Doesn't have an address book

    Guest
    Negative
    1

    Only IMAP. No support for local folders.

    3 of 4 comments
    • Geary is Free and Open SourceThunderbird is also Free and Open Source
    • Geary is LightweightThunderbird is not according to our users
  8. Mailspring icon

    Mailspring

     118 likes

    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.

    50 Mailspring alternatives

    Cost / License

    Application type

    Platforms

    • Mac
    • Windows
    • Linux
    • Arch Linux
    • Fedora
    • Ubuntu
    Clean design with integrated search and swipe gestures
     
    |
    8
    Mailspring vs Thunderbird Comments
    Top Positive Comment
    3psilon
    1

    Great alternative, especially for casual users. Simple, streamlined UI, feels fresh.

    Top Negative Comment
    Shoji VR
    0

    paywall, not available for android/ios, not portable

    Matt Schaefer
    Negative
    0

    Unable to even find an address book or ability to import a csv file from previous mail client. You lose me when things are made so "modern-clean" that I have to consult a manual or Google things.

    3 of 8 comments
    • Mailspring is Freemium and Open SourceThunderbird is Free and Open Source
  9. Sylpheed icon

    Sylpheed

     61 likes

    Sylpheed is a simple, lightweight but featureful, and easy-to-use e-mail client (mailer, MUA).

    Cost / License

    • Free
    • Open Source

    Application type

    Alerts

    • Discontinued

    Platforms

    • Mac
    • Windows
    • Linux
    • BSD
    • PortableApps.com
    Main screen
     
    |
    2
    Discontinued

    The latest beta version is from September 2022.

    Sylpheed vs Thunderbird Comments
    Guest
    Negative
    3

    It doesn't encrypt password storage and doesn't have Master Password function

    locogato
    Positive
    0

    Sypheed has been my email client for some 15 years, but its more recent lack of updating has been worrisome -- and got to a head now, because my account requires OAuth and Sypheed does not cover that. With much regret I must look for something else.

    • Sylpheed is Free and Open SourceThunderbird is also Free and Open Source
    • Sylpheed is LightweightThunderbird is not according to our users
  10. Pelton icon

    Pelton

     13 likes

    Free, open-source client for Windows, macOS, and Linux, offering local email storage and search online or offline, privacy-focused with no telemetry or third-party servers, IMAP and SMTP support, intuitive interface, and multiple account support.

    19 Pelton alternatives

    Cost / License

    Application type

    Platforms

    • Mac
    • Windows
    • Linux
    Pelton screenshot 1
     
  11. Aerion icon

    Aerion

     10 likes

    Modern open-source email client supporting unified inbox, IMAP/SMTP, Gmail and Outlook with OAuth2, conversation threading, rich text TipTap composing, CardDAV contact sync, tracking removal, dark mode, color themes, vim-style shortcuts, and a detachable window.

    Cost / License

    Application type

    Platforms

    • Mac
    • Windows
    • Linux
    • Flathub
    • Flatpak
    Aerion screenshot 1
     
  12. Mailpile icon

    Mailpile

     118 likes

    Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features. The development of Mailpile is funded by a large community of backers and all code related to the project is and will be released under an OSI approved Free Software license.

    Cost / License

    • Free
    • Open Source

    Application types

    Alerts

    • Discontinued

    Platforms

    • Linux
    • Online
    • Self-Hosted
    • OpenPGP
    Mailpile screenshot 1
     
  13. Mutt icon

    Mutt

     68 likes

    Mutt is a small but very powerful text-based mail client for Unix operating systems. Some of its features are: color support, message threading, MIME support (including RFC2047 support for encoded headers), PGP/MIME (RFC2015), various features to support mailing lists, including...

    55 Mutt alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Mac
    • Windows
    • Linux
    • Xfce
    Mutt screenshot 1
     
    |
    2
    Mutt vs Thunderbird Comments
    Guest
    Negative
    17

    Thunderbird users want a GUI mail application. Mutt is a command line mail application. They are both good and both popular, but very much apples and oranges.

    Guest
    Negative
    -2

    Mutt's a great email client for your terminal, not a GUI app like Thunderbird.

    • Mutt is Free and Open SourceThunderbird is also Free and Open Source
  14. KMail icon

    KMail

     49 likes

    KMail is the email component of Kontact, the integrated personal information manager of KDE. Kontact is a personal information manager and groupware software suite for KDE. It supports calendars, contacts, notes, to-do lists, news, and email.

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Linux
    • BSD
    KMail screenshot 1
     
    |
    1
    KMail vs Thunderbird Comments
    1victor
    Positive
    0

    Well integrated with the KDE ecosystem

    • KMail is Free and Open SourceThunderbird is also Free and Open Source
    • KMail is LightweightThunderbird is not according to our users
12 of 29 Thunderbird alternatives