The best free alternative to Thunderbird is K-9 Mail, which is also Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to Thunderbird and loads of them is free so hopefully you can find a suitable replacement. Other interesting free alternatives to Thunderbird are Claws Mail, Evolution, Betterbird and SeaMonkey.
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.
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.
K-9 Mail is not for desktop operating systems, only Android. So you can't replace Thunderbird unless you are also replacing your desktop with a mobile device.
K9 has nothing to do here. It's an android app
Most users think K-9 Mail is a great Thunderbird alternative.
K-9 Mail is the most popular Android & Android Tablet alternative to Thunderbird.
K-9 Mail is the most popular Open Source & free alternative to Thunderbird.
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.
Despite the style, Claws is super fast and allow you to programs it with Perl and Python which is great for marketing automation.
No HTML compose is the only reason I don't switch to it. We're not in 1980 anymore.
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.
Most users think Claws Mail is a great Thunderbird alternative.
Claws Mail is the most popular Windows & Linux alternative to Thunderbird.
Evolution is a personal information management application that provides integrated mail, calendaring, address book and task list functionality.
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.
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.
Unfortunately, only available on Linux, not on Windows, not on MacOS. Otherwise promising.
Most users think Evolution is a great Thunderbird alternative.
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.
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.
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!
It has many fixes for long existing bugs
Almost everyone thinks Betterbird is a great Thunderbird alternative.
Betterbird is the most popular Mac alternative to Thunderbird.
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.
SeaMonkey is both a WEB BROWSER and EMAIL CLIENT. It's the successor of Mozilla Application Suite or Netscape Communicator, resp. Further it includes also a news client program, an HTML editor (SeaMonkey Composer) and an IRC client (ChatZilla).
It has all of Thunderbird's features and many more.
Unfortunately doesn't support synchronization with CardDAV address books.
Some users think SeaMonkey is a great Thunderbird alternative, some don't.
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.
A good Windows alternative if you use 1-2 mailboxes or don't mind paying.
doesnt support Linux, isnt open source, not configurable enough
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
Most users think eM Client is a great Thunderbird alternative.
Geary is an email application built around conversations, for the GNOME 3 desktop.
Geary is a lot lighter than Thunderbird, so it's a good choice on lower-end hardware. IMAP features are basic, but 90% of what most people will need. It relies on GNOME for contacts, but the mail app itself can run on any Linux desktop.
Doesn't have an address book
Only IMAP. No support for local folders.
Most users think Geary is a great Thunderbird alternative.
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.
I have used Thunderbird with IMAP for years, but the tiny font problem on Mac is now a dealbreaker, and with my decades of emails and folders, Thunderbird is flailing when fetching ail or moving folders. Apple Mail does what I need it to: manage multiple Gmail accounts, not be too slow, and let me adjust font size. The arrangement of folders/mailboxes in Apple Mail is not as intuitive as Tbird but I can deal with that.
You must download all your emails and there is no option to limit it!
Some users think Apple Mail is a great Thunderbird alternative, some don't.
Apple Mail is the most popular Web-based, iPhone & iPad alternative to Thunderbird.
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.
While I do use FairEmail on my mobile devices and like it, it is not a valid alternative to Thunderbird which is for desktop platforms.
wrong platform. FairEmail is not an alternative for Thunderbird users because it only runs on android. Thunderbird is for desktop operating systems only.
Most users think FairEmail is a great Thunderbird alternative.
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.
Mailbird is missing most of the features which Thunderbird offers, like encryption and plugins
Clean interface, much faster than Thunderbird. One touch unsubcribe is a nice touch and adding new accounts is a breeze
Great design. Great features
Some users think Mailbird is a great Thunderbird alternative, some don't.
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.
Great alternative, especially for casual users. Simple, streamlined UI, feels fresh.
Need to create an account on a third-party company to access your email.
Unable to even find an address book or ability to import a csv file from previous mail client. You lose me when things are made so "modern-clean" that I have to consult a manual or Google things.
Most users think Mailspring is a great Thunderbird alternative.
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.
Free, simple, reliable, easy to manage multiple accounts, fair amount of customization, synchronisation, templates
no sorting, dont show allmail for gmail
Most users think Spark Mail is a great Thunderbird alternative.
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Keeps the style of working with email as it should be, like we are used to from proper desktop Mail clients. It's unlike modern fancy clients with couple of buttons without even providing an option to view headers.