What’s New
• Add-ons: Added support for specifying a cookieStoreId when creating a space
What’s Changed
• CardDAV address books and calendars now use the same OAuth2 code as mail
• Ignore unsupported subkeys/signatures when importing compliant OpenPGP keys
• Add-ons: browser.messages.listAttachments() now returns attachment headers
• Set show missed reminders preference to false by default
What’s Fixed
• Race condition in folder compaction could cause unexpected behavior
• Link at about:rights pointed to Firefox privacy policy instead of Thunderbird's
• On Windows, the Restart button in the About dialog failed to update Thunderbird
• Compacting an empty folder failed with write error
• Compacting of IMAP folder with corrupted local storage failed with write error
• POP3 'fetch headers only' and 'get selected messages' could delete messages
• Data corruption occurred when compacting IMAP Drafts folder after saving a message
• Users may not have been notified if messages arrived in multiple folders at once
• 'Search Online' checkbox in saved search properties was incorrectly disabled
• Dragging threaded emails to another folder left a summary in the message panel
• POP3 status message showed incorrect download count when messages were deleted
• Thunderbird could show incorrect 'From' and 'To' fields for mailing list emails
• mail.compose.other.header wrongly added fields to message preview pane headers
• Space bar did not always advance to the next unread message
• Folder creation or renaming failed due to incorrect preference settings
• Message list scrolled to the wrong place on start-up
• After restart, all restored tabs with opened PDFs showed the same attachment
• Forwarding/editing S/MIME drafts/templates unusable due to regression
• Shutdown could hang due to unterminated search execution
• Sort order in 'Search Messages' panel reset after search or on first launch
• Reply window added an unnecessary third blank line at the top
• Thunderbird spell check box did not allow ENTER to accept suggested changes
• Thunderbird did not warn when replying to a 'noreply' address containing a '+'
• Context menu was unable to move email address to a different field
• 'Please fill out this field' in account setup always appeared in English
• Add-ons: Links in content pages with a target attribute loaded a blank page
• Double clicking a new contact icon added the contact to the address book twice
• Long email subject lines could overlap window control buttons on macOS
• POP3 'fetch headers only' and 'get selected messages' could skip some messages
• Thunderbird logged network errors in console when used in offline mode
• 'Prefer client-side email scheduling' needed to be selected twice
• Calendar print misaligned days (Mon-Sun) with their correct dates
• All-day event dates were displayed with times when they should not have times
• Duplicate invitations were sent if CALDAV calendar email case did not match
• Thunderbird calendar failed to show attendee as busy when added to an event
• Exceptions during CalDAV item processing would halt subsequent item handling
• Visual and UX improvements
• Security fixes