Release Notes

Support dark reader for the message pane

Removed obsolete preference extensions.overlayloader.loglevel

Increased the auto-compaction threshold to reduce frequency of compaction

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

Subscribe/Unsubscribe buttons were removed from the IMAP subscribe dialog

Fixed startup crash related to mailbox parsing

Folder corruption could cause Thunderbird to freeze and become unusable

IMAP could crash when reading cached messages

Enabling "Show Folder Size" on Maildir profile could render Thunderbird unusable

Folder compaction was not abandoned on shutdown

Recently deleted messages could become undeleted if message compaction failed

Message corruption could be propagated when reading mbox

Messages corrupted by folder compaction were only fixed by user intervention

Reading a message from past the end of an mbox file did not cause an error

View -> Folders had duplicate F access keys

Total message count for favorite folders did not work consistently

Collapsed NNTP thread incorrectly indicated there were unread messages

Disabling "Grouped by sort" while group header selected could break message pane

Switching from "All", "Unread", and "Threads with unread" did not work

Navigating to next unread message did not wait for all messages to be loaded

Folder compaction did not clean up on failure

Add-ons adding columns to the message list could fail and cause display issue

Could not open attached file in a MIME encrypted message

Unable to send an unencrypted response to an OpenPGP encrypted message

Remote content notifications were broken with encrypted messages

Updating criteria of a saved search resulted in poor search performance

Drag and drop of OS folders as attachments was not prevented

Unable to generate QR codes when exporting to mobile in some cases

Opening the Account Manager produced console error

Account creation "Setup Documentation" link was broken

QR codes were not scannable by Android app when using most high-contrast themes

Operating system reauthentication was missing when exporting QR codes for mobile

New mail notification was not hidden after reading the new message

Windows "Notifications & actions" did not display the Thunderbird icon

"Empty trash on exit" and "Expunge inbox on exit" did not always work

Message could disappear after moving from IMAP folder followed by Undo and Redo

Global database did not work immediately after update to Thunderbird 133

Drop-downs may not work in some places

Primary password prompt cancellation during mobile export was confusing

Calendar display times could be incorrect

Selected calendar day did not move forward at midnight

Could not drag all-day events from one day to another in week view

Calendar could show mixed languages in month display

Calendar displayed incorrect first day of the week

Visual and UX improvements

Security fixes