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Yahoo Mail alternatives · Email

Open-source alternatives to Yahoo Mail

Yahoo Mail is not described as open source on its own site. 39 of the 125 other email apps in this directory are open source, according to their own sites.

Yahoo Mail has a free plan. Paid plans start at $5 per month (Yahoo Mail Plus). 33 of them are free or have a free plan.

39 tools · Listings checked up to Nov 13, 2026 · Where the facts come from

The 12 closest to Yahoo Mail

  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. Yahoo Mail starts at $5 per month (Yahoo Mail Plus).
    • Only Proton Mail lists macOS, Windows and Linux apps.
    • Proton Mail is open source and end-to-end encrypted, according to its own site.
    • Proton Mail also covers calendar.
    Proton Mail vs Yahoo MailProton Mail pricing and details

  2. Inbox Zero

    Open source AI email assistant for Gmail and Outlook

    • Inbox Zero starts at $18 per user / month, billed annually ($20 billed monthly). Yahoo Mail starts at $5 per month (Yahoo Mail Plus).
    • Yahoo Mail 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

  3. Wino Mail

    Free, open source mail and calendar app for Windows

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

  4. Zero Mail

    Open-source AI email client that connects your existing inboxes

    • Zero Mail starts at $20 per month (billing basis not shown). Yahoo Mail starts at $5 per month (Yahoo Mail Plus).
    • Only Yahoo Mail lists iOS and Android apps.
    • Zero Mail is open source and self-hostable, according to its own site.
    • Yahoo Mail also covers tasks.
    Zero Mail pricing and details

  5. Thunderbird

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

    • Thunderbird is free. Yahoo Mail starts at $5 per month (Yahoo Mail Plus).
    • Only Thunderbird lists Windows, macOS and Linux apps.
    • Only Yahoo Mail lists a web app.
    • Only Yahoo Mail lists an iOS app.
    Thunderbird pricing and details

  6. Zimbra

    Self-hosted email, calendar and file sharing for organizations

    • Yahoo Mail 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.
    • Zimbra also covers calendar.
    Zimbra pricing and details

  7. Claws Mail

    Lightweight GTK email and news client, free under the GPL

    • Claws Mail is free. Yahoo Mail starts at $5 per month (Yahoo Mail Plus).
    • Only Claws Mail lists Linux and Windows apps.
    • Only Yahoo Mail lists a web app.
    • Only Yahoo Mail lists iOS and Android apps.
    Claws Mail pricing and details

  8. Sylpheed

    Lightweight desktop email client built on GTK+

    • Sylpheed is free. Yahoo Mail starts at $5 per month (Yahoo Mail Plus).
    • Only Sylpheed lists Windows, macOS and Linux apps.
    • Only Yahoo Mail lists a web app.
    • Only Yahoo Mail lists iOS and Android apps.
    Sylpheed pricing and details

  9. Open-Xchange

    OX App Suite email platform sold to providers and governments

    • Yahoo Mail has a free plan. Open-Xchange does not.
    • Only Yahoo Mail lists iOS and Android apps.
    • Open-Xchange is open source and self-hostable, according to its own site.
    • Open-Xchange also covers calendar.
    Open-Xchange pricing and details

  10. Horde

    Free open-source webmail, calendar, contacts and tasks suite

    • Horde is free. Yahoo Mail starts at $5 per month (Yahoo Mail Plus).
    • Only Yahoo Mail lists iOS and Android apps.
    • Horde is open source and self-hostable, according to its own site.
    • Horde also covers notes and calendar.
    Horde pricing and details

  11. Kolab Now

    Swiss-hosted email, calendars, contacts and tasks

    • Kolab Now starts at CHF 9.90 per month (Group Account). Yahoo Mail starts at $5 per month (Yahoo Mail Plus).
    • Yahoo Mail has a free plan. Kolab Now does not, though it has a free trial.
    • Only Yahoo Mail lists iOS and Android apps.
    • Kolab Now is open source, according to its own site.
    Kolab Now pricing and details

  12. Cypht

    Open-source webmail that combines many accounts in one inbox

    • Cypht is free. Yahoo Mail starts at $5 per month (Yahoo Mail Plus).
    • Only Yahoo Mail lists iOS and Android apps.
    • Cypht is open source and self-hostable, according to its own site.
    • Yahoo Mail also covers tasks.
    Cypht pricing and details

27 more that are open source

All 39 in one table

Common questions

Is there an open-source alternative to Yahoo Mail?

Yes. Proton Mail, Inbox Zero, Wino Mail, Zero Mail, Thunderbird, Zimbra, Claws Mail, Sylpheed and 31 more are open source, according to their own sites.

Is Yahoo Mail open source?

Yahoo Mail is not described as open source on its own site. The listing was checked on Oct 9, 2026 against the pages it cites.

Which of these email apps are free?

Proton Mail, Wino Mail, Zero Mail, Thunderbird, Claws Mail, Sylpheed, Horde, Cypht and 25 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 13, 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 Yahoo Mail: the alternatives its listing names first, then the tools that share the most features with it.