Open Source Microsoft Mail and Calendar AlternativesEmail Clients & Calendar Apps like Microsoft Mail and Calendar

The best open source alternative to Microsoft Mail and Calendar is Thunderbird. If that doesn't suit you, our users have ranked more than 50 alternatives to Microsoft Mail and Calendar and many of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to Microsoft Mail and Calendar are Betterbird, Fossify Calendar, Evolution and SeaMonkey.

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Alternatives list

  1. Thunderbird icon

    Thunderbird

     2563 likes

    Cross-platform email client supporting multiple identities, chat, and strong filtering. Extend functionality with add-ons like RSS/Atom feed readers and PGP support.

    88 Thunderbird alternatives

    Cost / License

    Application types

    Platforms

    • Mac
    • Windows
    • Linux
    • Android
    • BSD
    • AppImageHub
    • Snapcraft
    • Flathub
    • PortableApps.com
    • F-Droid
    • Haiku
    • Homebrew
    • Chocolatey
    Thunderbird screenshot 1
     
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    5
    Thunderbird vs Microsoft Mail and Calendar Comments
    Top Positive Comment
    Kelson V
    1

    Thunderbird's more stable in my experience, certainly more capable, the 2023 UI update has improved matters quite a bit, plus I had a much easier time tying it to my Nextcloud calendar and contacts. It's a bit heavier, but that's balanced out by the other benefits. Plus Thunderbird will also run on other platforms.

    Top Negative Comment
    SWMANNN
    3

    It is just too big, has a steeper learning curb, and bloated for the user population that MS M&C targets. It rather is an alternative to MS Outlook.

    Guest
    Negative
    3

    We need to open it to receive emails. I t cannot run in baground.

    Review by a new / low-activity user.
    3 of 5 comments
    • Thunderbird is Free and Open SourceMicrosoft Mail and Calendar is Free and Proprietary
    • Thunderbird is Customizable and Privacy focusedMicrosoft Mail and Calendar is not according to our users
  2. Betterbird icon

    Betterbird

     82 likes

    Betterbird, a soft fork of Mozilla Thunderbird, improves user experience with advanced features, bug fixes, security patches, and multi-row descriptions similar to Outlook. Compatible with multiple platforms and can be used alongside Thunderbird, sharing the same profile.

    30 Betterbird alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Mac
    • Windows
    • Linux
    • Flathub
    • Chocolatey
    Betterbird screenshot 1
     
  5. Evolution icon

    Evolution

     208 likes

    Evolution is a personal information management application that provides integrated mail, calendaring, address book and task list functionality.

    70 Evolution alternatives

    Cost / License

    Application types

    Platforms

    • Linux
    • BSD
    • Flathub
    • S/MIME
    • GNOME
    • OpenPGP
    Mail
     
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    1
    Evolution vs Microsoft Mail and Calendar Comments
    SWMANNN
    Negative
    2

    Can't replace MS M&C since it doesn't support Windows

    • Evolution is Free and Open SourceMicrosoft Mail and Calendar is Free and Proprietary
  6. SeaMonkey icon

    SeaMonkey

     242 likes

    Web-browser, advanced e-mail, newsgroup and feed client, IRC chat, and HTML editing in one application. Itis built on the open source Mozilla Gecko engine, the same code which underlies Thunderbird and is the base for the Firefox browser.

    187 SeaMonkey alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Mac
    • Windows
    • Linux
    • BSD
    • PortableApps.com
    SeaMonkey screenshot 1
     
  7. Geary icon

    Geary

     106 likes

    Geary is an email application built around conversations, for the GNOME 3 desktop.

    48 Geary alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Linux
    • BSD
    • Flathub
    • GNOME
    • Flatpak
    Main window
     
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    1
    Geary vs Microsoft Mail and Calendar Comments
    Ferociter
    Negative
    1

    The closest to Windows Mail and Calendar; yet doesn't support windows.

    • Geary is Free and Open SourceMicrosoft Mail and Calendar is Free and Proprietary
    • Geary is Lightweight and Privacy focusedMicrosoft Mail and Calendar is not according to our users
  9. Claws Mail icon

    Claws Mail

     106 likes

    Email and news client on GTK+ foundation featuring quick performance, extensible plugins, secure protocols, advanced filtering, strong folder and contact management, lightweight design, powerful search, customizable interface, multi-language support, and encryption.

    64 Claws Mail alternatives

    Cost / License

    • Free
    • Open Source

    Application types

    Platforms

    • Windows
    • Linux
    • BSD
    The main window
     
  10. Mailpile icon

    Mailpile

     118 likes

    Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features. The development of Mailpile is funded by a large community of backers and all code related to the project is and will be released under an OSI approved Free Software license.

    59 Mailpile alternatives

    Cost / License

    • Free
    • Open Source

    Application types

    Alerts

    • Discontinued

    Platforms

    • Linux
    • Online
    • Self-Hosted
    • OpenPGP
    Mailpile screenshot 1
     
  11. Right Calendar icon

    Right Calendar

     10 likes

    Right Calendar app is a versatile scheduling tool that offers unparalleled flexibility to its users. One of its standout features is that it is built on an open-source platform. This not only ensures transparency but also allows for constant updates and bug fixes from a...

    Cost / License

    Application type

    Platforms

    • Android
    Right Calendar screenshot 1
     
  12. Kontact icon

    Kontact

     37 likes

    Personal Information Manager (Mail, Contact, Calendar and more).

    Cost / License

    • Free
    • Open Source

    Application types

    Platforms

    • Linux
    • Flathub
    Kontact screenshot 1
     
  13. Wino Mail icon

    Wino Mail

     8 likes

    Wino is a lightweight native mail client for Windows 10/11. It is still in active development. Main motivation for this project is to replace Mail & Calendar for Windows with modern Windows design without using web technologies for speed.

    22 Wino Mail alternatives

    Cost / License

    Application type

    Platforms

    • Windows
    Wino Mail screenshot 1
     
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    1
    Wino Mail vs Microsoft Mail and Calendar Comments
    stepgray4
    Positive
    1

    Clearly designed from Windows Mail and Calendar, it has a very simple and easy to use interface, making it ideal to replace Windows Mail.

    Review by a new / low-activity user.
    • Wino Mail is Freemium and Open SourceMicrosoft Mail and Calendar is Free and Proprietary
    • Wino Mail is LightweightMicrosoft Mail and Calendar is not according to our users
  14. Nextcloud Mail icon

    Nextcloud Mail

     13 likes

    💌 Mail app for Nextcloud.

    Cost / License

    Application type

    Platforms

    • Online
    • Self-Hosted
    • Nextcloud
     
12 of 31 Microsoft Mail and Calendar alternatives