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Mailbird alternatives · Email

Open-source alternatives to Mailbird

Mailbird is not described as open source on its own site. 8 of the 51 other email apps in this directory are open source, according to their own sites.

Mailbird has a free plan. Paid plans start at $34.49 per year (Premium Yearly Plan, US Mac App Store in-app price). 6 of them are free or have a free plan.

8 tools · Listings checked up to Oct 9, 2026 · Where the facts come from

How each one differs from Mailbird

  1. Thunderbird

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

    • Thunderbird is free. Mailbird starts at $34.49 per year (Premium Yearly Plan, US Mac App Store in-app price).
    • Only Thunderbird lists Linux and Android apps.
    • Thunderbird is open source, according to its own site.
    • Mailbird can be bought with a one-time purchase.
    Thunderbird vs MailbirdThunderbird pricing and details

  2. Mailspring

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

    • Mailspring starts at $8 per month, or $85 per year (Mailspring Pro). Mailbird starts at $34.49 per year (Premium Yearly Plan, US Mac App Store in-app price).
    • Only Mailspring lists a Linux app.
    • Mailspring is open source, according to its own site.
    • Mailbird can be bought with a one-time purchase.
    Mailspring vs MailbirdMailspring pricing and details

  3. Wino Mail

    Free, open source mail and calendar app for Windows

    • Only Mailbird lists a macOS app.
    • Wino Mail is open source, according to its own site.
    • Mailbird can be bought with a one-time purchase.
    • Wino Mail also covers templates, tasks and calendar.
    Wino Mail vs MailbirdWino Mail pricing and details

  4. FairEmail

    Open source, privacy-oriented email client for Android

    • FairEmail starts at $7.49 one-time (pro features, US Google Play in-app purchase). Mailbird starts at $34.49 per year (Premium Yearly Plan, US Mac App Store in-app price).
    • Only FairEmail lists an Android app.
    • Only Mailbird lists Windows and macOS apps.
    • FairEmail is open source and end-to-end encrypted, according to its own site.
    FairEmail pricing and details

  5. Inbox Zero

    Open source AI email assistant for Gmail and Outlook

    • Inbox Zero starts at $18 per user / month, billed annually ($20 billed monthly). Mailbird starts at $34.49 per year (Premium Yearly Plan, US Mac App Store in-app price).
    • Mailbird has a free plan. Inbox Zero does not, though it has a free trial.
    • Only Inbox Zero lists a web app.
    • Only Inbox Zero lists iOS and Android apps.
    Inbox Zero pricing and details

  6. 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. Mailbird starts at $34.49 per year (Premium Yearly Plan, US Mac App Store in-app price).
    • Only Proton Mail lists a web app.
    • Only Proton Mail lists Linux, iOS and Android apps.
    • Proton Mail is open source and end-to-end encrypted, according to its own site.
    Proton Mail pricing and details

  7. Tuta Mail

    End-to-end encrypted email and calendar from Germany

    • Tuta Mail starts at €3 per month, paid yearly (lowest paid personal plan). Mailbird starts at $34.49 per year (Premium Yearly Plan, US Mac App Store in-app price).
    • Only Tuta Mail lists a web app.
    • Only Tuta Mail lists Linux, iOS and Android apps.
    • Tuta Mail is open source and end-to-end encrypted, according to its own site.
    Tuta Mail pricing and details

  8. Posteo

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

    • Posteo starts at €1 per month, prepaid (minimum top-up €12). Mailbird starts at $34.49 per year (Premium Yearly Plan, US Mac App Store in-app price).
    • Mailbird has a free plan. Posteo does not.
    • Only Posteo lists a web app.
    • Only Mailbird lists Windows and macOS apps.
    Posteo pricing and details

Common questions

Is there an open-source alternative to Mailbird?

Yes. Thunderbird, Mailspring, Wino Mail, FairEmail, Inbox Zero, Proton Mail, Tuta Mail and Posteo are open source, according to their own sites.

Is Mailbird open source?

Mailbird is not described as open source on its own site. The listing was checked on Oct 5, 2026 against the pages it cites.

Which of these email apps are free?

Thunderbird, Mailspring, Wino Mail, FairEmail, Proton Mail and Tuta Mail 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 Oct 9, 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 Mailbird: the alternatives its listing names first, then the tools that share the most features with it.