Mozilla Thunderbird is a fully featured, secure and very functional email client and RSS feed reader. It lets you handle mail efficiently and with style, and Thunderbird filters away junk mail too. It offers a pretty and streamlined interface to a very powerful email package.

Not only is Thunderbird a secure email client, a sophisticated and very well integrated Bayesian spam filter knocks out most junk mail (after some training). Combine these two aspects of Thunderbird, and you get a sensible feature that automatically sanitizes (potentially dangerous) HTML code and turns off remote images for spam or anything else - worms, viruses - you classify as bad mail. Though not perfect, a scam sensor detects tactics commonly used to fool users.

Flexible views, free-form tags and powerful filters, search and virtual folders (which also work fine with IMAP accounts and across email accounts) make it a snap to handle large amounts of mail. The integrated RSS feed reader extends these abilities to news.

Is Thunderbird free?

Yes, Mozilla Thunderbird is free and open source. You can use it for personal and commercial use. However, Mozilla is open to donations in order to keep improving the app.

Does Thunderbird let users make a local copy of my messages?

Yes, Thunderbird will keep a copy of all your messages on your computer by default. You can also create a local backup of your messages or download them from your server whenever you need it.

Can Thunderbird replace Outlook?

For general email use, yes, Thunderbird can be a suitable replacement for Outlook. Those that require better integration with Microsoft Office and Exchange will be more satisfied with Microsoft Outlook. Additionally, Thunderbird's interface may not be as polished as Outlook's.

How many email accounts can I have with Thunderbird?

Thunderbird has no limitation on the number of email accounts users can add to the app.

What mail services does Thunderbird support?

Thunderbird supports most mailing services that synchronize items through the IMAP protocol or download messages through the POP3 protocol. The application also supports synchronization for MS Exchange and accounts. Thunderbird supports Gmail, iCloud,, IceWarp, Microsoft Exchange, Yahoo, AOL, GMX, Kerio and more.



If you like Firefox's tabbed browsing, you're going to love tabbed email. Tabbed email lets you load emails in separate tabs so you can quickly jump between them. Perhaps you're responding to an email and need to refer back to an earlier email. Tabbed email lets you keep multiple emails open for easy reference.

Double-clicking or hitting enter on a mail message will now open that message in a new tab window. Right-clicking on messages or folders will open them in a tab in the background.

When quitting Thunderbird, visible tabs will be saved and will be restored when you open Thunderbird the next time. There is also a new Tab menu on the Tab toolbar to help you switch between Tabs.


The new search interface in Thunderbird 3 contains filtering and timeline tools to pinpoint the exact email you're looking for. Thunderbird 3 also indexes all of your emails to help you search even faster. Your search results are displayed in a tab so you can easily switch back and forth to your search results and other email.

Message Archive

If you think you're going to need an email in the future but want it out of your inbox without deleting it, archive it! Archiving helps you manage your inbox and put your email into a new archive folder system.

Selecting the Archive button or hitting the 'A' key will archive your email.

Customize Your Email Experience

Thunderbird is flexible to suit your personality, to give you the features you need, and to fit your work style. Change how Thunderbird looks or add as many features as you want.

Thunderbird Look & Feel

With Personas, lightweight "skins" allow you to change the look and feel of Thunderbird in an instant. Hundreds of skins are available from the latest movies, famous landmarks, and Japanese tattoos. You can also choose from several Themes that dress up all the different icons in Thunderbird.

Smart Folders

Smart Folders helps you manage multiple email accounts by combining special folders like your Inbox, Sent, or Archive folder. Instead of going to the Inbox for each of your mail accounts, you can see all of your incoming email in one Inbox folder.

Add-ons Manager

Find and install add-ons directly in Thunderbird. You no longer need to visit the add-ons Web site---instead simply fire up the Add-ons Manager. Not sure which add-on is right for you? Ratings, recommendations, descriptions and pictures of the add-ons in action help you make your selection.

What's New


  • Thunderbird on Windows now requires Windows 10 or higher
  • Thunderbird on macOS now requires macOS 10.15 or higher
  • Updated message pane customization defaults for new profiles


  • All menu items in "Help" menu were disabled after sending a message on macOS
  • Pane splitter was still enabled for hidden folder pane
  • Folder tree expanded under drag-and-drop did not re-collapse when item was dropped
  • Deleting messages from message list sometimes scrolled list to bottom, selecting bottommost message
  • Ascending/descending message sorting was not available in vertical view
  • Message list was not updated when message was deleted from server outside of Thunderbird
  • Message header was occasionally missing in message preview
  • Message composer title was not visible on macOS when theme was enabled
  • Context menu with "Copy link" option was not available in calendar event descriptions
  • Improved localization of OpenPGP strings
  • "OK" and "Cancel" buttons were mostly hidden in address book Edit List dialog
  • Various visual and UX improvements