Thunderbird is a free, open-source, cross-platform application for managing email and news feeds. It is a local (rather than a web-based) email application that is powerful yet easy-to-use. Thunderbird is developed, tested, translated and supported by the folks at Mozilla Corporation and by a group of dedicated volunteers. Thunderbird gives you control and ownership over your email. There are lots of add-ons available for Thunderbird that enable you to extend and customize your email experience.
Thunderbird gives you IMAP/POP support, a built-in RSS reader, support for HTML mail, powerful quick search, saved search folders, advanced message filtering, message grouping, labels, return receipts, smart address book LDAP address completion, import tools, and the ability to manage multiple e-mail and newsgroup accounts.
An Archive feature similar to the one in GMail
Lightning fast search
What’s new in Thunderbird 78.1.0:
OpenPGP support is now feature complete. Improvements: new Key Wizard, online searching for OpenPGP keys, and more
The preferences tab now has a search field
Dark background in message reader is now disabled
Thunderbird startup was slow when using folder color customizations with many folders.
Previously configured colors will not be migrated.
Mail quota usage in status bar did not support terabyte folder sizes
Changing Junk mail settings with keyboard toggled wrong setting
Advanced IMAP server preferences not saved in Account Manager
Address book migration updates and fixes
Address book: Last Modified Date was not updated
Dark mode improvements
Various security fixes
Mail header toolbar (Reply, Forward, Archive, Junk buttons) no longer configurable
Fixed width font not working in compose window
Thunderbird version 78.1.0 is only offered as direct download from thunderbird.net and not as an upgrade from Thunderbird version 68 or earlier. A future release will provide updates from earlier versions. Automatic updates are available for users already running version 78.0 or higher.
Add-on support: As of version 78.0, Thunderbird only supports MailExtensions. Your favorite add-ons may not have been updated for compatibility.
At this time, users of the Enigmail Add-on should not update to Thunderbird 78.
OpenPGP in Thunderbird 78.1.0 has reached feature complete state, but it’s still disabled by default, to allow more time for testing, correctness, and localization. See the wiki for how to enable and help with testing.
Mozilla Thunderbird 78.1.0
Mozilla Thunderbird 52.9.1
Mozilla Thunderbird 17.0.9 ESR（企业版）
Mozilla Thunderbird 3.1.20