Release Notes

New Account Hub for centralized account setup

Redesigned recipient address fields (To, Cc, Bcc) as single-line input fields (pills) for multiple addresses instead of one line per address. More improvements to come.

Color customization of Folder Pane icons

Allow selecting messages via selection boxes instead of classic selection. "Select Messages" column needs to be selected via the thread pane's column picker.

"Delete" action column in thread pane (message list). "Select Messages" column needs to be selected via the thread pane's column picker.

Themes can be previewed in the Add-On Manager

Minimize to tray support added for Windows

New config option to anonymize message date header

Global Search menu item in app menu

Additional Enterprise policies

Calendar: Added ICS import support to -file command line option

Calendar: Add event preview to ICS import dialog

Chat: OTR messaging support

Chat: IRC echo-message capability

Add-on support: As of version 78.0, Thunderbird only supports MailExtensions and MailExtension Experiments. Restartless add-ons and non-restartless legacy add-ons using XUL overlays are no longer supported.

**As of version 78.0, "sideloaded" extensions are no longer supported. Enterprise administrators can deploy extensions using policies.

Linux minimum runtime requirements have changed: GTK 3.14, GLIBC 2.17, libstdc++ 4.8.1 Details

Thunderbird Options/Preferences tab redesigned and with new user interface

Account creation dialog redesigned and with new user interface

Account Manager moved to a tab

Add-ons manager with new user interface and notifications

Improved "Recent" folder list for "Move to" and "Copy to" in message context menu

Improved UI of global search results tab

Improvements to the location bar of a tab displaying web pages

Use scalable icons throughout Thunderbird to improve support for HiDPI monitors and dark mode

Address books are now stored as SQLite databases to prepare for future addressbook improvements. Existing address books in MAB format (using a Mork database) will be converted.

New parser and formatter for vCard. vCard versions 3.0 and 4.0 are now supported.

Various theme and dark mode improvements

Various look and feel improvements

Improved dialog for folder compaction (purging of deleted messages)

Graphics hardware acceleration is now enabled by default

TLS 1.0 and 1.1 disabled

Calendar: The Lightning calendar add-on is now integrated into Thunderbird

Calendar: Lightning version removed from Thunderbird user agent string

Calendar: Web Calendar Access Protocol (WCAP) support removed

Calendar: Storage access is now asynchronous to improve performance

Calendar: Location URLs are now clickable

Addon Developers: Updates to and expansion of MailExtensions APIs. Details

Password display font had characters that were difficult to read

When copying messages from an IMAP folder to a local folder, offline store wasn't used

While Thunderbird was in safe mode, the help menu did not offer an item to restart with add-ons enabled

Mailbox quotas not displayed correctly

Images not rotated when composing a message

Email addresses sometimes displayed incorrectly in message composer

Many accessibility fixes and improvements: message composer, account setup, attachment pane

Mailbox format conversion fixes

Address book improvements: exporting, editing contacts, contact photos

Chat: Renaming contacts in context menu did not work

Calendar: Task and event dialogs were sometimes too small for their content

Calendar: URLs in the event reminder dialog were not clickable

Various security fixes

Mail header toolbar (Reply, Forward, Archive, Junk buttons) no longer configurable

Preferences search not available

Drag and drop of address book contacts not working in some situations