Release Notes

Implemented enterprise policy to allow granular in-app notification control

New mail alert now includes message disposition buttons

Added 'Mark as Read' and 'Delete' actions to mail notifications

Added 'Mark as Spam' and 'Mark as Starred' actions to mail notifications

Support dark reader for the message pane

Messages are automatically adapted to dark mode with a quick toggle in the header

Message filters are now available in the Folder Pane context menu

Added horizontal threadpane scrolling mail.threadpane.table.horizontal_scroll

Implemented customizable row count for Cards View in 'Appearance' settings

Implemented ability to manually sort folders in the folder pane

New "Appearance" Settings UI to globally control message threading/sorting order

Added checkbox to select/unselect all calendars in the calendar setup wizard

Account Hub enabled by default for second email setup

Add-ons: Added support for specifying a cookieStoreId when creating a space

Added Thunderbird-specific loading symbol

Removed obsolete preference extensions.overlayloader.loglevel

CardDAV address books and calendars now use the same OAuth2 code as mail

Display junk state and allow toggling it from top of message context menu

Subscribe/Unsubscribe buttons were removed from the IMAP subscribe dialog

Ignore unsupported subkeys/signatures when importing compliant OpenPGP keys

Some generic appearance settings were moved from General to Appearance section

Add-ons: browser.messages.listAttachments() now returns attachment headers

Set calendar.alarms.showmissed preference to false by default

Exporting a calendar to .ics did not include the calendar name

Chrome URLs were opened in an external browser

Race condition in folder compaction could cause unexpected behavior

Crash could occur when shutting down during MAPI send

Message preview truncation in notifications improved

Thunderbird could crash when setting message compose headers

Links in the OAuth authentication window did not open when clicked

Mail window could stop functioning during and after folder compaction

Error message for compacting a corrupted local folder was not useful

Repair folder did not fix mbox files produced on MacOS before Thunderbird 1.0

Wrong day of week displayed for some emails

Edit menu entries missing when group header selected in "Grouped by sort" view

IMAP folder "Undelete" performed "Delete" when mixed messages were selected

View Message Source no longer worked for multiple selected messages

Creating a new mail account from the menu bar in a message window failed

Feed subscriptions were broken

Feed body was not rendered when "Message Body As" formatting option selected

Thunderbird could show incorrect 'From' and 'To' fields for mailing list emails

mail.compose.other.header wrongly added fields to message preview pane headers

Deleting or detaching attachments in a saved .eml file appeared to work but failed

In RSS feeds, the space bar did not scroll the message like it did in emails

Unchecking "Show all headers" in Message Header Settings closed dialog

Some webpage links could be forced to open in Thunderbird

Right-click of message in cross-folder virtual folder wrongly selected it

Messages deleted from a cross-folder search view could not be undeleted

Cards view "replies" button remained styled without new messages in thread

Subscribe window "Show items that contain" should not have been shown for IMAP

POP3 inbox could show new mail with no subject, no sender, and date 1970-01-01

Folders at level 3+ were not auto-discovered when IMAP subscriptions were ignored

New subfolder did not inherit parent view, sort order, sort type, or columns

With "Fetch headers only" enabled, messages could not be sorted by size

Selecting starred messages did not update immediately

Marking a unified folder as favorite did not show it in favorite folders

Threaded search view was not updated correctly when sorted by date received

Menu items to manage folders were not disabled in offline mode

Ctrl or Shift selecting multiple messages reset when dragging across a message

Folder was hidden from Favorite when subfolder was removed

Folder tree message counts displayed incorrectly under certain conditions

The UI could falsely report a message as encrypted when a null cipher was used

Message security panel strings were used in the wrong places

Importing an OpenPGP public key with whitespace failed

Unable to open attached signed OpenPGP .eml message

OpenPGP key was not updated when accepted key was reimported with new identities

Dual signed (PGP and S/MIME) emails were not displayed

"Secret Key ID" field did not sanitize input, causing draft encryption to fail

Could not send signed/encrypted messages in some setups due to regression

Quick Filter did not display loading symbol when search was in progress

Search messages dialog list could not be sorted by clicking the header icon

Repaired folders were not reindexed for search after repair

Messages with multiple authors or no author were not indexed for global search

Messages from authors without email address were not indexed for global search

Shutdown could hang due to unterminated search execution

Changing a saved draft's send identity did not prompt to save the modified message

Thunderbird did not warn when replying to a 'noreply' address containing a '+'

Invite attachments without a name were forwarded as 'Attached Message Part'

Creating a link from selected text did not work with advanced properties selected

Spellcheck no longer highlighted misspelled words in the compose window

Changing the UI font size did not apply to some dialogs

Deleted Gmail messages stayed visible until compact/expunge, despite settings

Notification duration preference enabled when system notifications were enabled

Chat settings tab remained visible when mail.chat.enabled was false

macOS system notifications worked but email alerts could not be disabled separately

Setting different archiving options for multiple identities did not work

OAuth2 not shown in "Authentication method" menulist for existing Exchange account

'Please fill out this field' in account setup always appeared in English

No gap existed between Back and Forward buttons in the Feed Account Wizard dialog

Moving back in the calendar import dialog could break the Continue button

Add-ons: Links in content pages with a target attribute loaded a blank page

Add-ons: Context menu entries were incorrectly aligned.

Add-ons: Optional permission prompts for WebExtensions displayed wrong permissions

Double clicking a new contact icon added the contact to the address book twice

Unable to auto-discover Address Book on Radicale server

CardDAV synchronization to Zimbra server failed

Mark-Of-The-Web was not applied to attachments saved via drag and drop

System search toggle did not properly reflect and control integration state

Some messages could not be scrolled due to hidden overflows in inline styles

Keyboard navigation was not possible when first header button was disabled

Thunderbird could crash when renaming a local folder while copying from IMAP

Some functionality was missing for newsgroup messages opened from a file or URI

Message and folder lists could display incorrect line spacing after restart

Automatic compact did not attempt to compact all folders when error encountered

APOP authenication for POP3 did not prompt for corrected password

POP3 'fetch headers only' and 'get selected messages' could skip some messages

Thunderbird logged network errors in console when used in offline mode

Slow performance when moving bulk messages from IMAP to local

Crossposting news article was not possible if newsgroups on different servers

Cancelling a post to a news server could fail and remove the article

Thunderbird could crash in NNTP subscription dialog

Newsgroup searches with slashes were not supported with XPAT-enabled servers

Offline newsgroup use lacked functionality needed for effective offline access

Thunderbird could show a misleading error message on IMAP login failure

Modal alerts shown for expired articles when downloading news for offline use

Status bar message did not include newsgroup name along with the account name

Reconnecting to an NNTP server was potentially not possible

Nickserv messages appeared during successful authentication

Thunderbird Flatpak install did not use a branded symbolic icon

Unable to view full certificate chain from the "View Signature" button

Organizer email address for CalDAV calendar events could be incorrect

Changing calendar.week.start preference did not update calendar views

Clicking a mid: link in Calendar opened two copies of the message

Clicking a 'mid:' link in event created from message did not work

Thunderbird calendar failed to show attendee as busy when added to an event

Some calendar requests were blocked due to opaque response blocking

Visual and UX improvements

Security fixes

Passwords are not remembered in 32-bit MAPI use without a compose window