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 15 are Calendar Apps so hopefully you can find a suitable replacement. Other interesting Calendar App alternatives to Thunderbird are Evolution, Betterbird, Microsoft Outlook and Spark Mail.

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Thunderbird alternatives are mainly Email Clients but may also be Calendar Apps or Web Browsers. Filter by these or use the filter bar below if you want a narrower list of alternatives or looking for a specific functionality of Thunderbird.

Thunderbird

2385

Email Client
Free • Open Source

Thunderbird is a free, open source, cross-platform e-mail, news and instant messaging client. The project strategy is modeled after Mozilla Firefox.

More about Thunderbird

Thunderbird alternatives page was last updated Sep 26, 2024

Claws Mail
Claws Mail is an email client (and news reader), based on GTK+, featuring

Quick response Graceful, and sophisticated interface Easy configuration, intuitive operation Abundant features Extensibility Robustness and stability.
80 Claws Mail alternatives
License model
- Free • Open Source
Application types
- Email Client
- Calendar App
Platforms
- Windows
- Linux
- BSD
Top Claws Mail Features
1. Lightweight
2. Extensible by Plugins/Extensions
3. Multiple Account support
4. Spam Filter
5. No registration required
6. Ad-free
7. Privacy focused
8. Works Offline
9. Portable
10. Calendar Integration
11. GPG Encryption
12. Import/Export OPML Feeds
Show all NaN Claws Mail features ▾
Claws Mail VS Thunderbird
Is Claws Mail a good alternative to Thunderbird?
Comments about Claws Mail as an Alternative to Thunderbird

Jonathan DUMONT
Despite the style, Claws is super fast and allow you to programs it with Perl and Python which is great for marketing automation.
Top positive comment •Aug 1, 2019
9
3psilon
It's a good, lightweight alternative, but the UI is clunky and it misses HTML message composing. You have been warned!
Top positive comment •Sep 3, 2017
14
Guest
No HTML compose is the only reason I don't switch to it. We're not in 1980 anymore.
Top negative comment •Sep 28, 2018
16
SViN
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.
Comment •Sep 20, 2023
1
Guest
very good alternative under linux. I can not say the same under windows since fancy plugin is very buggy.
Positive comment •May 5, 2020
-1
Show more comments
5 of 8 comments
- 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 Lightweight and Privacy focusedThunderbird is not according to our users

Evolution
Evolution is a personal information management application that provides integrated mail, calendaring, address book and task list functionality.
78 Evolution alternatives
License model
- Free • Open Source
Application types
- Email Client
- Calendar App
Platforms
- Linux
- BSD
- Flathub
- S/MIME
- GNOME
- OpenPGP
+4
Top Evolution Features
1. Calendar Integration
2. Contacts
3. CalDAV Support
4. Calendar View
5. Ad-free
6. Spam Filter
7. Multiple Account support
8. Sync with Google Calendar
9. Extensible by Plugins/Extensions
10. Dark Mode
11. Works Offline
12. GPG Encryption
Show all NaN Evolution features ▾
Evolution VS Thunderbird
Is Evolution a good alternative to Thunderbird?
Comments about Evolution as an Alternative to Thunderbird

Michel Th.
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.
Positive comment •Jan 30, 2023
1
Guest
well, I use cinnamon desktop, Thunderbird does not display 24 hour format but AM/PM for starters. Also, I use the built-in acount manager and Thunderbird does not "talk" with that as well.. Evolution does sync my CALDAV and CARDDAV from this. Thunderbird needs plugins for this and these plugins also make Thunderbird unstable (lightning). Since I like to keep things "clean", Evolution is my software of choice ATM...
Positive comment •Dec 20, 2019
1
Syntevo GmbH
Unfortunately, only available on Linux, not on Windows, not on MacOS. Otherwise promising.
Comment •Nov 18, 2022
0
Guest
Has a nice Gui, works fast and has many options. Still some functions are not intuitive. Good alternative to Thunderbird
Positive comment •Apr 16, 2021
0
- Most users think Evolution is a great Thunderbird alternative.
- Evolution is Free and Open SourceThunderbird is also Free and Open Source

Betterbird
Betterbird is a drop-in replacement for Mozilla Thunderbird. Betterbird has more features and more fixed bugs than Thunderbird.
28 Betterbird alternatives
License model
- Free • Open Source
Application types
- Email Client
- Calendar App
Platforms
- Mac
- Windows
- Linux
- Flathub
- Chocolatey
+8
Top Betterbird Features
1. Multiple Account support
2. Privacy focused
3. Lightweight
4. Extensible by Plugins/Extensions
5. Unified inbox
6. Works Offline
7. Ad-free
8. Support for Themes
9. Portable
10. PGP Encryption
11. No Tracking
12. Spam Filter
Show all NaN Betterbird features ▾
Betterbird VS Thunderbird
Is Betterbird a good alternative to Thunderbird?
Comments about Betterbird as an Alternative to Thunderbird

Sam Lander
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.
Positive comment •May 31, 2023
2
HOT EARTH
Its Thunderbird, just Better. No Import needed, as it uses the same profile Folder!
Positive comment •Sep 5, 2022
4
Guest
It has many fixes for long existing bugs
Positive comment •Jun 20, 2024
1
Guest
No Thunderbird importation.
Negative comment •Sep 9, 2021
-6
- Most users think Betterbird is a great Thunderbird alternative.
- Betterbird is Free and Open SourceThunderbird is also Free and Open Source
- Betterbird is Privacy focused and LightweightThunderbird is not according to our users

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eM Client
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 y...

https://www.emclient.com
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Microsoft Outlook
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.
137 Microsoft Outlook alternatives
License model
- Paid • Proprietary
Application types
- Email Client
- Calendar App
Platforms
- Mac
- Windows
- Online
- Android
- iPhone
- Android Tablet
- iPad
- Apple Watch
- Android Wear
+7
Top Microsoft Outlook Features
1. Exchange
2. Native application
3. Email Organizer
4. Calendar Integration
5. Calendar View
6. Support for Aliases
7. Multiple Account support
8. Works Offline
9. Cloud Sync
10. Unified inbox
11. Dark Mode
12. Support for @mentions
Show all NaN Microsoft Outlook features ▾
Microsoft Outlook VS Thunderbird
Is Microsoft Outlook a good alternative to Thunderbird?
Comments about Microsoft Outlook as an Alternative to Thunderbird

Eyji
As a Firefox user, I have tried to love Thunderbird but it just can't compete with Outlook, IMHO.
Top positive comment •May 23, 2019
4
Guest
It works. Much less buggy. Better integration with Windows. Encryption/Signing.Works over remote desktop without losing pieces of itself. Search is crappier though.
Top positive comment •Feb 13, 2020
2
LinuxDoge
Not open source, not privacy-focused, no Linux support
Top negative comment •Mar 24, 2022
2
Guest
outlook is clumsy and bloated and does nothing well. tbird does one thing and well.
Negative comment •Jun 12, 2020
3
Guest
Outlook do not support RSS
Negative comment •Jul 28, 2016
0
- Some users think Microsoft Outlook is a great Thunderbird alternative, some don't.
- Microsoft Outlook is the most popular Web-based alternative to Thunderbird.
- Microsoft Outlook is the most popular commercial alternative to Thunderbird.
- Microsoft Outlook is Paid and ProprietaryThunderbird is Free and Open Source

Spark Mail
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.
63 Spark Mail alternatives
License model
- Freemium • Proprietary
Application types
- Email Client
- Calendar App
Platforms
- Mac
- Windows
- Android
- iPhone
- iPad
- Apple Watch
+3
Top Spark Mail Features
1. Multiple Account support
2. Email Scheduling
3. Snooze Mail
4. Cloud Sync
5. Dark Mode
6. Calendar Integration
7. Email Organizer
8. Works Offline
9. Unified inbox
10. Mail Filtering
11. Ad-free
12. Calendar View
Show all NaN Spark Mail features ▾
Spark Mail VS Thunderbird
Is Spark Mail a good alternative to Thunderbird?
Comments about Spark Mail as an Alternative to Thunderbird

folkomaton
Free, simple, reliable, easy to manage multiple accounts, fair amount of customization, synchronisation, templates
Positive comment •Apr 24, 2020
0
rmpbklyn
no sorting, dont show allmail for gmail
Negative comment •Jun 10, 2018
-3
- Most users think Spark Mail is a great Thunderbird alternative.
- Spark Mail is Freemium and ProprietaryThunderbird is Free and Open Source

eM Client
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 s...
64 eM Client alternatives
License model
- Freemium • Proprietary
Application types
- Email Client
- Calendar App
Platforms
- Mac
- Windows
- Android
+5
Top eM Client Features
1. IMAP Support
2. Calendar Integration
3. Multiple Account support
4. PGP Encryption
5. Exchange
6. Dark Mode
7. Unified inbox
8. Cloud Sync
9. Email Organizer
10. Sync with Google Calendar
11. Automatic Backup
12. CardDAV Support
Show all NaN eM Client features ▾
eM Client VS Thunderbird
Is eM Client a good alternative to Thunderbird?
Comments about eM Client as an Alternative to Thunderbird

3psilon
A good Windows alternative if you use 1-2 mailboxes or don't mind paying.
Top positive comment •Sep 3, 2017
2
Guest
Thunderbird is brutal, emClient is clean, neat, well thought out, etc. It works with Exchange, Gmail, etc. Everything in one install. Drop in replacement for Outlook at a fraction of the price for Business.
Top positive comment •Jul 31, 2017
6
LinuxDoge
doesnt support Linux, isnt open source, not configurable enough
Top negative comment •Mar 24, 2022
1
I am spezticle
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
Negative comment •Jan 16, 2023
1
Guest
closed source program that doesn't do a lot of what thunderbird can
Negative comment •Sep 4, 2022
0
Show more comments
5 of 12 comments
- Most users think eM Client is a great Thunderbird alternative.
- eM Client is Freemium and ProprietaryThunderbird is Free and Open Source

Microsoft Mail and Calendar
Windows 10 has Mail and Calendar apps already built in.
86 Microsoft Mail and Calendar alternatives
License model
- Free • Proprietary
Application types
- Email Client
- Calendar App
Platforms
- Windows
Microsoft Mail and Calendar Features
Run in background
Bundled with Windows
Unified inbox
Email tracking
Show all NaN Microsoft Mail and Calendar features ▾
+3
Discontinued
Mail and Calendar are being phased out and replaced by Outlook. They should be discontinued by the end of 2024.
Microsoft Mail and Calendar VS Thunderbird
Is this a good alternative to Thunderbird?
Comments about Microsoft Mail and Calendar as an Alternative to Thunderbird

Kelson V
Not as capable as Thunderbird, plus I had a harder time getting it to sync with my Nextcloud contacts and calendar. (Not that it'll matter for much longer, since Microsoft is discontinuing it soon anyway.)
Negative comment •Nov 28, 2023
0
RemovedUser
It runs in background unlike Outlook and other email clients.
Positive comment •Feb 9, 2021
2
- Most users think Microsoft Mail and Calendar is a great Thunderbird alternative.
- Microsoft Mail and Calendar is Free and ProprietaryThunderbird is Free and Open Source