Privacy Ratings
Search

Open-source email clients

15 email clients whose code is public under an OSI-approved license, rated for privacy with evidence. Picks first, then by score.

  1. Betterbird Grade B Our pick

    Fork of Mozilla Thunderbird that follows its Extended Support Releases and adds extra fixes and features. Available for Windows, macOS and Linux.

    MPL-2.0. Source code

  2. Delta Chat Grade A

    Decentralized messenger that uses email servers for delivery, with automatic end-to-end encryption through Autocrypt and OpenPGP. Works with chatmail relays or existing email accounts.

    The core library is MPL-2.0 and the apps are GPL-3.0. Source code

  3. aerc Grade B

    Terminal email client for Linux and macOS with IMAP, JMAP, Maildir and Notmuch support and PGP encryption through GnuPG.

    MIT. Source code

  4. Claws Mail Grade B

    Lightweight GTK email and news client for Linux and Windows, extended through plugins for OpenPGP, HTML rendering and spam filtering.

    GPL-3.0. Source code

  5. Evolution Grade B

    GNOME groupware application for Linux that combines email, calendar, contacts and tasks, with support for IMAP, POP3, Exchange and OpenPGP.

    LGPL-2.1. Source code

  6. KMail Grade B

    KDE email client for Linux, part of the Kontact suite, with support for IMAP, POP3, OpenPGP and S/MIME.

    GPL-2.0-or-later. Source code

  7. Mutt Grade B

    Text-based terminal email client for Unix-like systems with built-in IMAP, POP3 and SMTP support, message threading and OpenPGP and S/MIME encryption.

    GPL-2.0-or-later. Source code

  8. NeoMutt Grade B

    Terminal email client for Linux and macOS based on Mutt, with built-in IMAP, POP3, SMTP and OpenPGP support.

    GPL-2.0. Source code

  9. Thunderbird for Android Grade B

    Open-source email app for Android from the Thunderbird project, based on K-9 Mail, which remains available as a variant. Works with any IMAP, POP3 and SMTP provider.

    Apache-2.0. Source code

  10. Mozilla Thunderbird Grade B

    Open-source desktop email client for Windows, macOS and Linux with calendar, contacts and built-in OpenPGP and S/MIME encryption.

    MPL-2.0. Source code

  11. Alpine Grade B

    Text-based email client derived from Pine, for Unix-like systems and Windows, with built-in IMAP, POP3 and SMTP support and S/MIME encryption.

    Apache-2.0. Source code

  12. FairEmail Grade B

    Open-source email app for Android that works with any IMAP, POP3 and SMTP provider and supports multiple accounts with a unified inbox.

    GPL-3.0. Source code

  13. Himalaya Grade B

    Command-line email client that manages mail over IMAP, JMAP, SMTP, Maildir, the Gmail API and Microsoft Graph, with composing and reading handled by the companion MML tool.

    MIT or Apache-2.0. Source code

  14. Geary Grade B

    Email app for the GNOME desktop on Linux that groups messages into conversations and works with IMAP accounts.

    LGPL-2.1. Source code

  15. Sylpheed Grade C

    Lightweight GTK email client for Linux, Windows and macOS with POP3, IMAP and SMTP support, junk mail filtering and GnuPG encryption.

    GPL-2.0, with the LibSylph library under LGPL. Source code

Compare all 31 email clients, open source or not.