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Mailfence alternatives · Email

Open-source alternatives to Mailfence

Mailfence is not described as open source on its own site. 16 of the 73 other email apps in this directory are open source, according to their own sites.

Mailfence has a free plan. Paid plans start at €2.50 per month, billed yearly (Base). 13 of them are free or have a free plan.

16 tools · Listings checked up to Nov 12, 2026 · Where the facts come from

The 12 closest to Mailfence

  1. Proton Mail

    End-to-end encrypted email service based in Switzerland

    • Proton Mail starts at $3.99 per month, billed every 12 months ($47.88); $4.99 billed monthly. Mailfence starts at €2.50 per month, billed yearly (Base).
    • Only Proton Mail lists macOS, Windows and Linux apps.
    • Proton Mail is open source, according to its own site.
    • Mailfence also covers documents.
    Proton Mail vs MailfenceProton Mail pricing and details

  2. Tuta Mail

    End-to-end encrypted email and calendar from Germany

    • Tuta Mail starts at €3 per month, paid yearly (lowest paid personal plan). Mailfence starts at €2.50 per month, billed yearly (Base).
    • Only Tuta Mail lists Windows, macOS and Linux apps.
    • Tuta Mail is open source, according to its own site.
    • Mailfence also covers documents.
    Tuta Mail vs MailfenceTuta Mail pricing and details

  3. Posteo

    Ad-free, green-powered email from Berlin for €1 a month

    • Posteo starts at €1 per month, prepaid (minimum top-up €12). Mailfence starts at €2.50 per month, billed yearly (Base).
    • Mailfence has a free plan. Posteo does not.
    • Only Mailfence lists iOS and Android apps.
    • Posteo is open source, according to its own site.
    Posteo vs MailfencePosteo pricing and details

  4. Thunderbird

    Free, open-source email app for Windows, macOS, Linux and Android

    • Thunderbird is free. Mailfence starts at €2.50 per month, billed yearly (Base).
    • Only Thunderbird lists Windows, macOS and Linux apps.
    • Only Mailfence lists a web app.
    • Only Mailfence lists an iOS app.
    Thunderbird pricing and details

  5. FairEmail

    Open source, privacy-oriented email client for Android

    • FairEmail starts at $7.49 one-time (pro features, US Google Play in-app purchase). Mailfence starts at €2.50 per month, billed yearly (Base).
    • Only Mailfence lists a web app.
    • Only Mailfence lists an iOS app.
    • FairEmail is open source, according to its own site.
    FairEmail pricing and details

  6. Wino Mail

    Free, open source mail and calendar app for Windows

    • Only Wino Mail lists a Windows app.
    • Only Mailfence lists a web app.
    • Only Mailfence lists iOS and Android apps.
    • Wino Mail is open source, according to its own site.
    Wino Mail pricing and details

  7. Zimbra

    Self-hosted email, calendar and file sharing for organizations

    • Mailfence has a free plan. Zimbra does not.
    • Only Zimbra lists Windows, macOS and Linux apps.
    • Zimbra is open source and self-hostable, according to its own site.
    • Mailfence is end-to-end encrypted, according to its own site.
    Zimbra pricing and details

  8. Evolution

    GNOME's free mail, calendar and address book app

    • Evolution is free. Mailfence starts at €2.50 per month, billed yearly (Base).
    • Only Evolution lists a Linux app.
    • Only Mailfence lists a web app.
    • Only Mailfence lists iOS and Android apps.
    Evolution pricing and details

  9. Betterbird

    A fork of Thunderbird with extra features and bug fixes

    • Betterbird is free. Mailfence starts at €2.50 per month, billed yearly (Base).
    • Only Betterbird lists Windows, macOS and Linux apps.
    • Only Mailfence lists a web app.
    • Only Mailfence lists iOS and Android apps.
    Betterbird pricing and details

  10. Mailspring

    Open-source desktop email client for Mac, Windows and Linux

    • Mailspring starts at $8 per month, or $85 per year (Mailspring Pro). Mailfence starts at €2.50 per month, billed yearly (Base).
    • Only Mailspring lists macOS, Windows and Linux apps.
    • Only Mailfence lists a web app.
    • Only Mailfence lists iOS and Android apps.
    Mailspring pricing and details

  11. Inbox Zero

    Open source AI email assistant for Gmail and Outlook

    • Inbox Zero starts at $18 per user / month, billed annually ($20 billed monthly). Mailfence starts at €2.50 per month, billed yearly (Base).
    • Mailfence has a free plan. Inbox Zero does not, though it has a free trial.
    • Only Inbox Zero lists macOS and Windows apps.
    • Only Inbox Zero lists a browser extension.
    Inbox Zero pricing and details

  12. Zero Mail

    Open-source AI email client that connects your existing inboxes

    • Zero Mail starts at $20 per month (billing basis not shown). Mailfence starts at €2.50 per month, billed yearly (Base).
    • Only Mailfence lists iOS and Android apps.
    • Zero Mail is open source and self-hostable, according to its own site.
    • Mailfence is end-to-end encrypted, according to its own site.
    Zero Mail pricing and details

4 more that are open source

All 16 in one table

Common questions

Is there an open-source alternative to Mailfence?

Yes. Proton Mail, Tuta Mail, Posteo, Thunderbird, FairEmail, Wino Mail, Zimbra, Evolution and 8 more are open source, according to their own sites.

Is Mailfence open source?

Mailfence is not described as open source on its own site. The listing was checked on Oct 6, 2026 against the pages it cites.

Which of these email apps are free?

Proton Mail, Tuta Mail, Thunderbird, FairEmail, Wino Mail, Evolution, Betterbird, Mailspring and 5 more are free or have a free plan.

When was this checked?

Each listing shows its own date. On this page they run from Oct 4, 2026 to Nov 12, 2026. Vendors change prices and plans without notice, so confirm on their site before you buy.

This page is built from the listings. A tool is here because its listing says so, and the order is how close each is to Mailfence: the alternatives its listing names first, then the tools that share the most features with it.