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Mimestream alternatives · Email

Open-source alternatives to Mimestream

Mimestream 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.

Mimestream is a paid product with a free trial, starting at $49.99 per year, or $4.99 billed monthly. 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 Mimestream

  1. Mailspring

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

    • Mailspring starts at $8 per month, or $85 per year (Mailspring Pro). Mimestream starts at $49.99 per year, or $4.99 billed monthly.
    • Mailspring has a free plan. Mimestream does not, though it has a free trial.
    • Only Mailspring lists Windows and Linux apps.
    • Mailspring is open source, according to its own site.
    Mailspring pricing and details

  2. Wino Mail

    Free, open source mail and calendar app for Windows

    • Wino Mail has a free plan. Mimestream does not, though it has a free trial.
    • Only Wino Mail lists a Windows app.
    • Only Mimestream lists a macOS app.
    • Wino Mail is open source, according to its own site.
    Wino Mail pricing and details

  3. 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. Mimestream starts at $49.99 per year, or $4.99 billed monthly.
    • Proton Mail has a free plan. Mimestream does not, though it has a free trial.
    • Only Proton Mail lists a web app.
    • Only Proton Mail lists Windows, Linux, iOS and Android apps.
    Proton Mail pricing and details

  4. Thunderbird

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

    • Thunderbird is free. Mimestream starts at $49.99 per year, or $4.99 billed monthly.
    • Thunderbird has a free plan. Mimestream does not, though it has a free trial.
    • Only Thunderbird lists Windows, Linux and Android apps.
    • Thunderbird is open source, according to its own site.
    Thunderbird pricing and details

  5. Tuta Mail

    End-to-end encrypted email and calendar from Germany

    • Tuta Mail starts at €3 per month, paid yearly (lowest paid personal plan). Mimestream starts at $49.99 per year, or $4.99 billed monthly.
    • Tuta Mail has a free plan. Mimestream does not, though it has a free trial.
    • Only Tuta Mail lists a web app.
    • Only Tuta Mail lists Windows, Linux, iOS and Android apps.
    Tuta Mail pricing and details

  6. Posteo

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

    • Posteo starts at €1 per month, prepaid (minimum top-up €12). Mimestream starts at $49.99 per year, or $4.99 billed monthly.
    • Only Posteo lists a web app.
    • Only Mimestream lists a macOS app.
    • Posteo is open source and end-to-end encrypted, according to its own site.
    Posteo pricing and details

  7. FairEmail

    Open source, privacy-oriented email client for Android

    • FairEmail starts at $7.49 one-time (pro features, US Google Play in-app purchase). Mimestream starts at $49.99 per year, or $4.99 billed monthly.
    • FairEmail has a free plan. Mimestream does not, though it has a free trial.
    • Only FairEmail lists an Android app.
    • Only Mimestream lists a macOS app.
    FairEmail pricing and details

  8. Inbox Zero

    Open source AI email assistant for Gmail and Outlook

    • Inbox Zero starts at $18 per user / month, billed annually ($20 billed monthly). Mimestream starts at $49.99 per year, or $4.99 billed monthly.
    • Only Inbox Zero lists a web app.
    • Only Inbox Zero lists Windows, iOS and Android apps.
    • Only Inbox Zero lists a browser extension.
    Inbox Zero pricing and details

Common questions

Is there an open-source alternative to Mimestream?

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

Is Mimestream open source?

Mimestream is not described as open source on its own site. The listing was checked on Oct 4, 2026 against the pages it cites.

Which of these email apps are free?

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