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ImprovMX alternatives · Email

Open-source alternatives to ImprovMX

ImprovMX 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.

ImprovMX has a free plan. Paid plans start at $50 per year (Light, up to 5 domains). 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 ImprovMX

  1. SimpleLogin

    Open-source email aliases that forward to your own inbox

    • SimpleLogin starts at $36 per year ($4 billed monthly). ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Only SimpleLogin lists iOS and Android apps.
    • Only SimpleLogin lists a browser extension.
    • SimpleLogin is open source and self-hostable, according to its own site.
    SimpleLogin vs ImprovMXSimpleLogin pricing and details

  2. addy.io

    Email alias forwarding that hides your real address from sites

    • addy.io starts at $1 per month, billed yearly (Lite). ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Only addy.io lists iOS and Android apps.
    • Only addy.io lists a browser extension.
    • addy.io is open source and self-hostable, according to its own site.
    addy.io vs ImprovMXaddy.io pricing and details

  3. Inbox Zero

    Open source AI email assistant for Gmail and Outlook

    • Inbox Zero starts at $18 per user / month, billed annually ($20 billed monthly). ImprovMX starts at $50 per year (Light, up to 5 domains).
    • ImprovMX has a free plan. Inbox Zero does not, though it has a free trial.
    • Only Inbox Zero lists macOS, Windows, iOS and Android apps.
    • Only Inbox Zero lists a browser extension.
    Inbox Zero 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). ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Zero Mail is open source and self-hostable, according to its own site.
    • Zero Mail also covers email client.
    • ImprovMX also covers transactional email.
    Zero Mail pricing and details

  5. Claws Mail

    Lightweight GTK email and news client, free under the GPL

    • Claws Mail is free. ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Only Claws Mail lists Linux and Windows apps.
    • Only ImprovMX lists a web app.
    • Claws Mail is open source, according to its own site.
    Claws Mail pricing and details

  6. Sylpheed

    Lightweight desktop email client built on GTK+

    • Sylpheed is free. ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Only Sylpheed lists Windows, macOS and Linux apps.
    • Only ImprovMX lists a web app.
    • Sylpheed is open source, according to its own site.
    Sylpheed pricing and details

  7. Guerrilla Mail

    Disposable email inbox that needs no sign-up

    • Guerrilla Mail starts at $9.99 per year. ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Guerrilla Mail is open source, according to its own site.
    • ImprovMX also covers inbox filtering and transactional email.
    Guerrilla Mail pricing and details

  8. Cypht

    Open-source webmail that combines many accounts in one inbox

    • Cypht is free. ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Cypht is open source and self-hostable, according to its own site.
    • Cypht also covers email client.
    • ImprovMX also covers transactional email.
    Cypht pricing and details

  9. 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. ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Only Proton Mail lists macOS, Windows, Linux, iOS and Android apps.
    • Proton Mail is open source and end-to-end encrypted, according to its own site.
    • Proton Mail also covers calendar and email client.
    Proton Mail pricing and details

  10. Thunderbird

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

    • Thunderbird is free. ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Only Thunderbird lists Windows, macOS, Linux and Android apps.
    • Only ImprovMX lists a web app.
    • Thunderbird is open source, according to its own site.
    Thunderbird pricing and details

  11. Tuta Mail

    End-to-end encrypted email and calendar from Germany

    • Tuta Mail starts at €3 per month, paid yearly (lowest paid personal plan). ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Only Tuta Mail lists Windows, macOS, Linux, iOS and Android apps.
    • Tuta Mail is open source and end-to-end encrypted, according to its own site.
    • Tuta Mail also covers calendar and email client.
    Tuta Mail pricing and details

  12. Mailspring

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

    • Mailspring starts at $8 per month, or $85 per year (Mailspring Pro). ImprovMX starts at $50 per year (Light, up to 5 domains).
    • Only Mailspring lists macOS, Windows and Linux apps.
    • Only ImprovMX lists a web app.
    • Mailspring is open source, according to its own site.
    Mailspring pricing and details

27 more that are open source

All 39 in one table

Common questions

Is there an open-source alternative to ImprovMX?

Yes. SimpleLogin, addy.io, Inbox Zero, Zero Mail, Claws Mail, Sylpheed, Guerrilla Mail, Cypht and 31 more are open source, according to their own sites.

Is ImprovMX open source?

ImprovMX is not described as open source on its own site. The listing was checked on Nov 12, 2026 against the pages it cites.

Which of these email apps are free?

SimpleLogin, addy.io, Zero Mail, Claws Mail, Sylpheed, Guerrilla Mail, Cypht, Proton Mail 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 ImprovMX: the alternatives its listing names first, then the tools that share the most features with it.