Release Notes — Thunderbird

Release Notes

Thunderbird Desktop

Version 144.0 | Released October 14, 2025

Check out the notes below for this version of Thunderbird. As always, you’re encouraged to tell us what you think, ask for help, or file a bug in Bugzilla.

System Requirements: Details

  • Windows: Windows 10 or later
  • Mac: macOS 10.15 or later
  • Linux: GTK+ 3.14 or higher

What’s Changed

changed

Flatpak runtime has been updated to Freedesktop SDK 24.08

What’s Fixed

fixed

Copying text from some error alerts was not possible

fixed

Fastmail CalDAV app password access failed due to forced OAuth regression

fixed

Delete key failed to prevent deleting attachments in OpenPGP messages

fixed

Newly created folder was missing under "Recent" when moving a message

fixed

Sender avatar displayed incorrectly for 'Name' via address sender format

fixed

Sorting by threads only brought threads with unread top messages to the top

fixed

News message marked read after NNTP error prevented retrieval from server

fixed

Inbox 'Location' column was not translated in French locale installation

fixed

Not all headers were signed when creating digitally signed OpenPGP email

fixed

Users could not read mail signed with OpenPGP v6 and PQC keys

fixed

Testing a configured personal S/MIME certificate for a sub-identity did not work

fixed

Testing an S/MIME certificate did not work for an old invalid certificate

fixed

Changing identity in compose window caused modified draft not to be saved

fixed

Shift-click 'Compose Message To' on 'mailto' link did not open in plain text

fixed

Image preview in Insert Image dialog failed with CSP error for web resources

fixed

Thunderbird could crash in various scenarios

fixed

'Copy Message to' action in a newsgroup filter did not work

fixed

Thunderbird could not import profile located at the top level of zip file

fixed

Thunderbird did not clearly fail when importing profile from a bad source

fixed

No way to distinguish between Thunderbird Release/ESR in Windows registry

fixed

Multi-attachment delete/detach confirmation only cited first attachment

fixed

Thunderbird hung when auto-checking multiple accounts for new messages

fixed

Reply All button was missing when using a Microsoft Exchange account

fixed

Sending emails via servers with self-signed certificate did not work

fixed

Task reminders could fail for tasks without end dates or with shifted due dates

fixed

Could not copy an event in multiweek or month view by drag-and-drop

fixed

Calendar discovery with certificate error displayed multiple exceptions

fixed

Visual and UX improvements

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