Alternatives to Thunderbird for all platforms with Open Source License

  • K-9 Mail icon

    K-9 Mail

    K-9 is an open source email client for Android with multi-folder sync, email signatures, Bcc-to-self, return-address configuration...

    Open Source Android Android Tablet

  • SeaMonkey icon


    The SeaMonkey project is a community effort to develop the SeaMonkey all-in-one internet application suite. RAM-demand similar to...

    Open Source Mac Windows Linux BSD

  • Evolution icon


    Evolution is the official personal information manager and workgroup information management tool for GNOME. It combines e-mail...

    Open Source Linux BSD GNOME

  • Geary icon


    Geary is an email application built for GNOME 3. It allows you to read and send email with a simple, modern interface.

    Open Source Linux BSD GNOME

  • Claws Mail icon

    Claws Mail

    Claws Mail is an email client (and news reader), based on GTK+, featuring Quick response Graceful, and sophisticated...

    Open Source Windows Linux BSD Xfce

    • Small and quick and not flooded with choices!
      Guest 6/30/2016
  • Sylpheed icon


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

    Open Source Mac Windows Linux BSD

  • Mutt icon


    Mutt is a small but very powerful text-based mail client for Unix operating systems. Some of its features are: color support, message...

    Open Source Mac Windows Linux Xfce

  • FossaMail icon


    FossaMail is an Open Source, Mozilla Thunderbird -based mail, news and chat client for Windows and Linux, brought to you by...

    Open Source Windows Linux

  • Trojitá icon


    Trojitá, is a fast Qt IMAP e-mail client that respects open standards and facilitates modern technologies. Trojitá values...

    Open Source Windows Linux

  • Kontact - KMail icon

    Kontact - KMail

    KMail is the email component of Kontact, the integrated personal information manager of KDE. Kontact is a personal information manager...

    Open Source Mac Windows Linux BSD

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  • sup icon


    Sup is a console-based email client for people with a lot of email. It supports tagging, very fast full-text search, automatic...

    Open Source Linux

  • Columba icon

    Columba Discontinued

    Columba is an email client written in Java, featuring a user-friendly graphical interface with wizards and internalionalization...

    Open Source Mac Windows Linux BSD

  • mu icon


    mu is a tool for dealing with e-mail messages stored in the Maildir-format, on Unix-like systems. mu's main purpose is to help you...

    Open Source Mac Linux BSD

  • Mulberry icon

    Mulberry Discontinued

    Mulberry is a powerful, easy to use electronic mail (email) and calendar program that allows you to send, access, and manage email and...

    Open Source Mac Windows Linux

  • nPOPuk icon

    nPOPuk Discontinued

    nPOPuk is an ultra-small, but comprehensive, e-mail client that runs on a wide range of Windows-based operating systems

    Open Source Windows Windows Mobile

  • Balsa icon


    Balsa is an e-mail client for GNOME, highly configurable and incorporating all the features you would expect in a robust mail client.

    Open Source Linux Xfce

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