Thunderbird AlternativesOnly apps categorised as Calendar Apps

The best Calendar alternative to Thunderbird is Claws Mail, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to Thunderbird and 14 are Calendar Apps so hopefully you can find a suitable replacement. Other interesting Calendar App alternatives to Thunderbird are Evolution, Betterbird, eM Client and Spark Mail.

filter to find the best alternatives

Thunderbird alternatives are mainly Email Clients, but if you're looking for Calendar Apps or Contact Managers you can filter on that. Other popular filters include Linux, Open Source, iPhone, Windows, Windows + Open Source, Android and Free. You can also filter by region, for example EU-based alternatives if you prefer software developed in the European Union. These are just examples - use the filter bar below to find more specific alternatives to Thunderbird.
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Alternatives list

  1. Claws Mail icon
     106 likes
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    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.

    62 Claws Mail alternatives

    Cost / License

    • Free
    • Open Source

    Application types

    Platforms

    • Windows
    • Linux
    • BSD
     
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    8
    51
    Comments about Claws Mail as an Alternative to Thunderbird
    Top Positive Comment
    Jonathan DUMONT
    9

    Despite the style, Claws is super fast and allow you to programs it with Perl and Python which is great for marketing automation.

    Top Negative Comment
    Guest
    19

    No HTML compose is the only reason I don't switch to it. We're not in 1980 anymore.

    Review by a new / low-activity user.
    SViN
    2

    I think most people are using gmail accounts or outlook accounts to access their emails. Claws supports Oauth2 to access said accounts but the implementation, is a complete PAIN.

    I can only realistically recommend something like this if your email provider is not forcing Oauth2.

    I would like for the devs to get to work into making the experience of setting up an account with oauth as painless as thunderbird.

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    3 of 8 comments
    Thunderbird Icon
    Claws Mail icon
    • Most users think Claws Mail is a great Thunderbird alternative.

    • Claws Mail is the most popular Windows & Linux alternative to Thunderbird.

    • Claws Mail is Free and Open SourceThunderbird is also Free and Open Source
    • Claws Mail is LightweightThunderbird is not according to our users
  2. Evolution icon
     205 likes
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    Evolution is a personal information management application that provides integrated mail, calendaring, address book and task list functionality.

    69 Evolution alternatives

    Cost / License

    • Free
    • Open Source

    Application types

    Platforms

    • Linux
    • BSD
    • Flathub
    • S/MIME
    • GNOME
    • OpenPGP
     
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    5
    71
    Comments about Evolution as an Alternative to Thunderbird
    Top Positive Comment
    Michel Th.
    1

    I use both Thunderbird and Evolution, sometimes Claws-Mail. Evolution is the only one that can show the real "received" date in scams I have been receiving for months. In a today's scam Evolution shows "sent date" (falsified) 14-12-2019 and "received date" 30-01-2023 (evidently true). Thunderbird and Claws-Mail show 14-12-2019 in both columns.

    RemovedUser
    Positive
    0

    As someone who is forced to use M365 at work (but ditching it at home, I let my subscription lapse) this is the closest visually to Outlook. That's important to me. The workflow is essentially identical.

    Review by a new / low-activity user.
    Syntevo GmbH
    1

    Unfortunately, only available on Linux, not on Windows, not on MacOS. Otherwise promising.

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    3 of 5 comments
    Thunderbird Icon
    Evolution icon
    • Most users think Evolution is a great Thunderbird alternative.

    • Evolution is Free and Open SourceThunderbird is also Free and Open Source
  3. Betterbird icon
     70 likes
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    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.

    28 Betterbird alternatives

    Cost / License

    • Free
    • Open Source

    Application type

    Platforms

    • Mac
    • Windows
    • Linux
    • Flathub
    • Chocolatey
     
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    5
    16
    Comments about Betterbird as an Alternative to Thunderbird
    Top Positive Comment
    Sam Lander
    3

    Betterbird does everything that Thunderbird does (it's a soft fork), while improving bugs and features.

    Because it's a soft fork, it retains the security implementations of Thunderbird.

    Thunderbird actually implements many of the bug fixes created by Betterbird, but at a much slower pace.

    drummer_nrg
    Positive
    1

    Betterbird is actively updated by a previous Thunderbird developer and is a fully compatible fork of Thunderbird which fixes some outstanding bugs. My add-ons like keepassxc-mail work fine!

    Guest
    Positive
    2

    It has many fixes for long existing bugs

    Review by a new / low-activity user.
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    3 of 5 comments
    Thunderbird Icon
    Betterbird icon
    • Almost everyone thinks Betterbird is a great Thunderbird alternative.

    • Betterbird is the most popular Mac alternative to Thunderbird.

    • Betterbird is Free and Open SourceThunderbird is also Free and Open Source
    • Betterbird is LightweightThunderbird is not according to our users
  4. eM Client icon
     232 likes
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    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.

    61 eM Client alternatives

    Cost / License

    • Freemium (Pay once)
    • Proprietary

    Application types

    Platforms

    • Mac
    • Windows
    • Android
     
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    12
    74
    Comments about eM Client as an Alternative to Thunderbird
    Comment summary: eM Client presents a clean interface with more built-in functions than Thunderbird, making it appealing for Mac and Windows users who prioritize design. However, users criticize it for being closed source, not supporting Linux, and having limited free accounts. Concerns include slow email rendering and potential phishing risks detected by antivirus software. Thunderbird remains favored for advanced configurability while eM Client is considered a viable alternative if users don't mind these limitations.
    Top Positive Comment
    3psilon
    2

    A good Windows alternative if you use 1-2 mailboxes or don't mind paying.

    Top Negative Comment
    LinuxDoge
    1

    doesnt support Linux, isnt open source, not configurable enough

    I am spezticle
    Negative
    1

    After installing I got malwarebytes and AVG antivirus alerts containing threats of phishing with urls such as "http://walmartsurvys.us/apple-touch-icon-precomposed.png" by way of the eM Client executable "MailClient.exe" There was a dozen more of them

    Do not install this phishing trash

    Review by a new / low-activity user.
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    3 of 12 comments
    Thunderbird Icon
    eM Client icon
    • Most users think eM Client is a great Thunderbird alternative.

    • eM Client is Freemium and ProprietaryThunderbird is Free and Open Source
  5. Spark Mail icon
     137 likes
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    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.

    62 Spark Mail alternatives

    Cost / License

    • Freemium (Subscription)
    • Proprietary

    Application type

    Platforms

    • Mac
    • Windows
    • Android
    • iPhone
    • iPad
    • Apple Watch
     
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    2
    19
    Comments about Spark Mail as an Alternative to Thunderbird
    folkomaton
    Positive
    0

    Free, simple, reliable, easy to manage multiple accounts, fair amount of customization, synchronisation, templates

    Review by a new / low-activity user.
    rmpbklyn
    Negative
    -3

    no sorting, dont show allmail for gmail

    Thunderbird Icon
    Spark Mail icon
    • Most users think Spark Mail is a great Thunderbird alternative.

    • Spark Mail is Freemium and ProprietaryThunderbird is Free and Open Source
  6. Copy a direct link to this comment to your clipboard

    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.

    126 Microsoft Outlook alternatives

    Cost / License

    • Pay once or Subscription
    • Proprietary

    Application types

    Platforms

    • Mac
    • Windows
    • Online
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Apple Watch
    • Android Wear
     
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    5
    84
    Comments about Microsoft Outlook as an Alternative to Thunderbird
    Top Positive Comment
    Eyji
    4

    As a Firefox user, I have tried to love Thunderbird but it just can't compete with Outlook, IMHO.

    Top Negative Comment
    LinuxDoge
    3

    Not open source, not privacy-focused, no Linux support

    Guest
    Negative
    3

    outlook is clumsy and bloated and does nothing well. tbird does one thing and well.

    Review by a new / low-activity user.
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    3 of 5 comments
    Thunderbird Icon
    Microsoft Outlook icon
    • Some users think Microsoft Outlook is a great Thunderbird alternative, some don't.

    • Microsoft Outlook is the most popular commercial alternative to Thunderbird.

    • Microsoft Outlook is Paid and ProprietaryThunderbird is Free and Open Source
  7. Canary Mail icon
     28 likes
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    Canary can write your emails, prioritize what needs attention, silence spam & much more. Say hello to your Inbox Copilot!

    62 Canary Mail alternatives

    Cost / License

    • Freemium (Pay once or Subscription)
    • Proprietary

    Application type

    Platforms

    • Mac
    • Windows
    • Android
    • iPhone
    • Android Tablet
    • iPad
    • Apple Watch
     
  8. Zimbra Desktop icon
     32 likes
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    The free Zimbra Desktop client allows you to meld the online and offline worlds – storing and synching your email, calendar, contacts, files and documents in the cloud, yet having them locally accessible when on the road.

    Cost / License

    • Free Personal
    • Proprietary

    Application types

    Platforms

    • Mac
    • Windows
    • Linux
     
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    2
    8
    Comments about Zimbra Desktop as an Alternative to Thunderbird
    michael111
    Positive
    0

    tried it over a few weeks, all you need for office users

    Guest
    Positive
    -4

    This one goes beyond the features and qualities of Thunderbird which is the very reason I am looking for an alternative!

    Review by a new / low-activity user.
    Thunderbird Icon
    Zimbra Desktop icon
    • Most users think Zimbra Desktop is a great Thunderbird alternative.

    • Zimbra Desktop is Free Personal and ProprietaryThunderbird is Free and Open Source
  9. Foxmail icon
     19 likes
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    Foxmail is a free POP3 and IMAP4 e-mail client in English and Chinese for Windows systems.

    33 Foxmail alternatives

    Cost / License

    • Free
    • Proprietary

    Application types

    Platforms

    • Mac
    • Windows
     
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    1
    Comments about Foxmail as an Alternative to Thunderbird
    Guest
    Positive
    -2

    The UI interface is greater, it has many great functions like notes, calendars, tags, etc. It could use POP, IMAP and Exchange accounts.

    Review by a new / low-activity user.
    Thunderbird Icon
    Foxmail icon
    • Most users think Foxmail is a great Thunderbird alternative.

    • Foxmail is Free and ProprietaryThunderbird is Free and Open Source
  10. HCL Domino icon
     6 likes
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    An enterprise application server that integrates information into a single workspace, integrates also a full mail server

    Cost / License

    • Pay once
    • Proprietary

    Application types

    Platforms

    • Mac
    • Windows
    • Online
     
  11. Scribe Mail icon
     7 likes
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    Scribe is a small portable email client with an intergrated contact database and calendar. It supports all the major internet mail protocols and uses international standards where possible. Scribe doesn't required installing or uninstalled and can be used from a removable...

    Cost / License

    • Free
    • Open Source

    Application types

    Platforms

    • Mac
    • Windows
    • Linux
    • Haiku
     
  12. Copy a direct link to this comment to your clipboard

    Orbit Communicator is a client server application that's designed to be deployed locally on your desktop machine. It currently provides an integrated email / calendaring experience based on external IMAP mail sources.

    Cost / License

    • Free
    • Proprietary

    Application types

    Platforms

    • Mac
    • Linux
    • Self-Hosted
     
12 of 14 Thunderbird alternatives