Thunderbird Desktop
Version 151.0beta | Released May 6, 2026
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.
These notes apply to Thunderbird version 151 beta 3 released May 06, 2026.
System Requirements: Details
- Windows: Windows 10 or later
- Mac: macOS 10.15 or later
- Linux: GTK+ 3.14 or higher
What’s New
new
Enable Thundermail OAuth sign-in with account auto-configuration
new
Enable users to override OAuth provider details for EWS accounts
new
Tasks can be sorted by created or modified date
What’s Changed
changed
Reinstated default application check when Thunderbird starts
changed
OpenPGP public key no longer attached by default in signed-only messages
What’s Fixed
fixed
Thunderbird could crash when processing message headers
fixed
Thunderbird could crash on startup
fixed
Calendar view tabs were not properly keyboard accessible
fixed
Thunderbird could crash when processing new incoming messages
fixed
On macOS, dragging attachments out of Thunderbird created multiple copies
fixed
Some IMAP emails showed current time instead of correct received date
fixed
Search result count was missing when using 'Find in Message' or Ctrl+F
fixed
Reply with selected text lost formatting for HTML messages containing
fixed
Multipart/related attachments were not preserved when editing or forwarding
fixed
Forwarded malformed MIME email had empty body and extra attachment
fixed
OWL add-on description was not visible in Account Hub for non-en-US locales
fixed
Account Hub prompted for password after OAuth login, causing Outlook setup failure
fixed
Auto-discovered Account Hub values were not preserved for manual editing
fixed
Account Hub links for encryption and signature opened the wrong account
fixed
Virtual folders did not update correctly for filtered POP3 messages
fixed
Thunderbird could crash in spam filtering
fixed
Using thunderbird -compose with double quotes made last email address invalid
fixed
With auto-mark-read disabled, large mail still marked as read during load delay
fixed
It was not possible to create date-only all-day tasks
fixed
Task context menu (right-click) had several disabled menu items
fixed
'Current Tasks' view showed past and finished tasks instead of only unfinished
fixed
Visual and UX improvements
Fixed in beta 2
What’s Changed
changed
There are no Thunderbird changes requiring release notes in this release
Fixed in beta 3
What’s Changed
changed
There are no Thunderbird changes requiring release notes in this release
