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eM Client alternatives: 5 apps ranked by verified data

Facts checked Oct 25, 2026AppBreakup editorialHow we rank

Common reasons people leave eM Client: free version limited to home use and two accounts, and no Linux version. We ranked 5 alternatives by how directly each one replaces eM Client, then by reviews, real visits and how recently each app's facts were checked against its own website. Microsoft Outlook currently ranks first.

Quick comparison

#AppPricingOpen sourcePlatformsVerified factsScore
1Thunderbird logoThunderbirdOpen sourceYesWindows, macOS, Linux +15 of 562.6
2Mailspring logoMailspringFree plan + paidYesmacOS, Windows, Linux4 of 457.2
  1. Thunderbird logo

    1. ThunderbirdTop pick

    Best for: Desktop users who want a free, private, customisable mail and calendar app

    Open sourceWindows, macOS, Linux, Android

    62.6

    score / 100

    Why switch from eM Client

    Free and open source, with calendars and OpenPGP, also on Linux.

    Pros

    • Free, open source and funded by donations, with no ads
    • Built-in OpenPGP, calendar, filters and many add-ons
    • Runs on Windows, Mac, Linux and Android

    Cons

    • No web version and no released iOS app yet
    • Add-ons sometimes break after major updates
    • Exchange setups can need extra configuration
    Visit Thunderbird Details and reviews
    How this score is calculated
    Editorial fit ×0.387
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Thunderbird a good eM Client alternative?

    Verified facts

    5 of 5 verified
    Desktop platforms
    Windows, Linux, macOS
    Checked Oct 25, 2026thunderbird.net(opens source in a new tab)
    Price
    Free, funded by donations
    Checked Oct 25, 2026thunderbird.net(opens source in a new tab)
    Mobile app
    Open-source Android app
    Checked Oct 25, 2026thunderbird.net(opens source in a new tab)
    Android app origin
    Formerly K-9 Mail
    Checked Oct 25, 2026github.com(opens source in a new tab)
    Android app license
    Apache-2.0
    Checked Oct 25, 2026github.com(opens source in a new tab)
  2. Mailspring logo

    2. Mailspring

    Best for: Desktop users, especially on Linux, who want a modern free client

    Free plan + paidOpen sourcemacOS, Windows, Linux

    57.2

    score / 100

    Why switch from eM Client

    Open-source desktop client that also runs on Linux.

    Pros

    • Free and open source on Mac, Windows and Linux
    • Clean interface with themes and keyboard shortcuts
    • Pro adds tracking, templates and send later at a low price

    Cons

    • No mobile apps
    • Small team, so features arrive slowly
    • Limited native Exchange support
    Visit Mailspring Details and reviews
    How this score is calculated
    Editorial fit ×0.369
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.1585
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Mailspring a good eM Client alternative?

    Verified facts

    4 of 4 verified
    License
    GPL-3.0
    Checked Oct 25, 2026github.com(opens source in a new tab)
    Pro price
    $8 per month
    Checked Oct 25, 2026getmailspring.com(opens source in a new tab)
    Platforms
    Mac, Windows, Linux
    Checked Oct 25, 2026getmailspring.com(opens source in a new tab)
    Pro features
    Read receipts, link tracking, send later
    Checked Oct 25, 2026getmailspring.com(opens source in a new tab)

The best eM Client alternative for…

The highest-ranked app in this list for each need.

Microsoft Outlook logo

Best eM Client alternative for most people

Microsoft Outlook

The standard choice if you need full Exchange and Microsoft 365 features.

Thunderbird logo

Best eM Client alternative for a free option

Thunderbird

Free and open source, with calendars and OpenPGP, also on Linux.

Mailbird logo

Best eM Client alternative for a free plan you can upgrade

Mailbird

A Windows and Mac client focused on app integrations and a unified inbox.

Mailspring logo

Best eM Client alternative for open source

Mailspring

Open-source desktop client that also runs on Linux.

Spark logo

Best eM Client alternative for Mac

Spark

Adds mobile apps and team collaboration across platforms.

Microsoft Outlook logo

Best eM Client alternative for Windows

Microsoft Outlook

The standard choice if you need full Exchange and Microsoft 365 features.

Thunderbird logo

Best eM Client alternative for Linux

Thunderbird

Free and open source, with calendars and OpenPGP, also on Linux.

Microsoft Outlook logo

Best eM Client alternative for iPhone and Android

Microsoft Outlook

The standard choice if you need full Exchange and Microsoft 365 features.

Microsoft Outlook logo

Best eM Client alternative for working in the browser

Microsoft Outlook

The standard choice if you need full Exchange and Microsoft 365 features.

eM Client alternatives: common questions

What is the best alternative to eM Client?

Microsoft Outlook ranks first right now. The standard choice if you need full Exchange and Microsoft 365 features. Thunderbird and Mailbird follow it in our ranking.

Is there a free alternative to eM Client?

Yes. Microsoft Outlook (free plan + paid), Thunderbird (open source), Mailbird (free plan + paid) and Mailspring (free plan + paid) have a free option. Check each app's verified facts for current plan limits.

Is there an open-source alternative to eM Client?

Yes: Thunderbird and Mailspring.

Which eM Client alternatives work on Linux?

Thunderbird and Mailspring run on Linux.

Why do people switch from eM Client?

The complaints we hear most: free version limited to home use and two accounts; no Linux version; business licensing is per device.

How is this list ranked?

Every app is scored with the same published formula: how directly it replaces eM Client, reviews (weighted by verification), visits from AppBreakup, how recently its facts were checked against its own website, and reader votes.