Thunderbird AlternativesTop Email Clients & Calendar Apps like Thunderbird

One of the most popular alternatives to Thunderbird is Betterbird, which is free and open source. Other popular alternatives are K-9 Mail, Evolution, Microsoft Outlook and SeaMonkey. There's no shortage of Email Clients like Thunderbird, with more than 100 alternatives for Windows, Mac, Linux, Android and iPhone.

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Most Thunderbird alternatives are Email Clients, but you can also narrow the list to Calendar Apps or Contact Managers. Other popular filters are iPhone, Linux, Open Source, Android and Windows. You can also filter for EU-based alternatives if you prefer software from the European Union.
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Alternatives
Thunderbird alternatives page was last updated

Alternatives list

  1. Mailbird icon
    Sponsored
     308 likes

    Streamline your email experience by managing multiple accounts, integrating apps like Slack and Google Calendar, and using AI-driven features like drafting and spam prevention. Customize your workspace with themes, notifications, and tools for improved productivity and a modern interface.

    More about Mailbird on AlternativeTo83 Mailbird alternatives

    Cost / License

    • Freemium
    • Proprietary

    Application type

    Since

    • Since 2013

    Platforms

    • Windows
    • Mac
    • US flagUnited States
    Mailbird screenshot 1
    Good alternative?
     
  2. Betterbird icon
     96 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.

    46 Betterbird alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Since

    • Since 2021

    Platforms

    • Windows
    • Mac
    • Linux
    • Flathub
    • Chocolatey
    Good alternative?
     
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    7
  3. K-9 Mail icon
     376 likes

    K-9 is an open source email client for Android with multi-folder sync, email signatures, Bcc-to-self, return-address configuration, keyboard shortcuts, Exchange Support, message flagging, IMAP deletes, saving attachments, configurable notifications and more.

    53 K-9 Mail alternatives

    Cost / License

    Application type

    Since

    • Since 2009

    Platforms

    • Android
    • Android Tablet
    • F-Droid
    • OpenAPK
    Good alternative?
     
    |
    23
  4. Evolution icon
     215 likes

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

    79 Evolution alternatives

    Cost / License

    Application type

    Since

    • Since 2009

    Platforms

    • Linux
    • BSD
    • GNOME
    • OpenPGP
    • S/MIME
    • Flathub
    Good alternative?
     
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    5
  5. Streamline emails, calendars, contacts, and task management with a smart inbox prioritizing critical messages. Includes calendar scheduling, third-party app integration like Facebook, Dropbox, and Trello, and support for Microsoft Exchange, Outlook.com, and Gmail, ensuring efficient task and email handling.

    158 Microsoft Outlook alternatives

    Cost / License

    • Paid
    • Proprietary

    Application type

    Since

    • Since 1996

    Platforms

    • Windows
    • Mac
    • Online
    • Android
    • iPhone
    • iPad
    • Android Tablet
    • Apple Watch
    • Android Wear
    Good alternative?
     
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    6
  6. SeaMonkey icon
     251 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.

    198 SeaMonkey alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Since

    • Since 2009

    Platforms

    • Windows
    • Mac
    • Linux
    • BSD
    • PortableApps.com
    Good alternative?
     
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    4
  7. FairEmail icon
     95 likes

    Open-source, privacy-focused email client offering features such as encryption via OpenPGP and S/MIME, unlimited accounts, a unified inbox, customizable settings, and reformatted emails to prevent phishing. Supports two-way synchronization and provides Pro features for additional customization.

    51 FairEmail alternatives

    Cost / License

    Application type

    Since

    • Since 2018

    Platforms

    • Android
    • Android Tablet
    • F-Droid
    • OpenAPK
    Good alternative?
     
    |
    2
  8. eM Client icon
     237 likes

    Looking for a full-featured email client with a modern and easy-to-use interface? Look no further than eM Client. Rated 3 out of 5, eM Client is a popular alternative to Thunderbird, offering all the features you need to manage your email, calendar, tasks, contacts, notes, and chat all in one place.

    With support for IMAP, calendar integration, and multiple accounts, eM Client is the perfect choice for users who want a robust email client that can handle all their needs. Whether you're using Windows or Mac, eM Client is the most popular proprietary alternative to Thunderbird, offering a powerful and flexible solution for managing your email and staying organized. Give it a try today and see why so many users are making the switch to eM Client.

    79 eM Client alternatives

    Cost / License

    • Freemium
    • Proprietary

    Application type

    Since

    • Since 2009

    Platforms

    • Windows
    • Mac
    • Android
    Good alternative?
     
    |
    13
  9. Penguin Mail icon
     21 likes

    Mail and calendar for Linux. Gmail and IMAP accounts, Google Calendar, contacts, OpenPGP and S/MIME. GTK4 and libadwaita, written in Rust.

    Cost / License

    Application type

    Since

    • New

    Platforms

    • Mac
    • Linux
    • Snapcraft
    Good alternative?
     
  10. Spark Mail icon
     144 likes

    E-mail app with all the great features: swipes (long/short), snooze, add (multiple) attachments from the cloud, support for various e-mail services and more.

    86 Spark Mail alternatives

    Cost / License

    • Freemium
    • Proprietary

    Application type

    Since

    • Since 2016

    Platforms

    • Windows
    • Mac
    • Android
    • iPhone
    • iPad
    • Apple Watch
    Good alternative?
     
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    2
  11. Apple Mail icon
     249 likes

    Access, view and manage messages from all your email accounts in one place. Categorize your messages into easy to browse categories. Catch up on email easily with Apple Intelligence powered Priority Messages and summarizations.

    137 Apple Mail alternatives

    Cost / License

    • Free
    • Proprietary

    Application type

    Since

    • Since 2009

    Platforms

    • Mac
    • Online
    • iPhone
    • iPad
    • Apple Watch
    Good alternative?
     
    |
    2
  12. Pelton icon
     18 likes

    Free, open-source client for Windows, macOS, and Linux, offering local email storage and search online or offline, privacy-focused with no telemetry or third-party servers, IMAP and SMTP support, intuitive interface, and multiple account support.

    Cost / License

    Application type

    Since

    • Since 2026

    Platforms

    • Windows
    • Mac
    • Linux
    Good alternative?
     
  13. Mailspring icon
     118 likes

    Boost your productivity and send better email with Mailspring, a beautiful, fast email client for Mac, Windows, and Linux. Mailspring is free to use and an optional pro version adds read receipts, send later, reminders and more.

    Cost / License

    Application type

    Since

    • Since 2017

    Platforms

    • Windows
    • Mac
    • Linux
    • Ubuntu
    • Arch Linux
    • Fedora
    Good alternative?
     
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    8
12 of 112 Thunderbird alternatives