Thunderbird Desktop
Version 148.0beta | Released January 14, 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 148 beta 3 released January 28, 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
Accessiblity is improved in various tree views
new
'Favorites' added as destination for 'Move To' and 'File' buttons
new
NTLM is exposed as an available authentication method for EWS accounts
What’s Changed
changed
Read folders are now removed from Unread Folders view
What’s Fixed
fixed
Periodic new mail checks silently stopped after sleep or network outages
fixed
Donation banner stole focus when Thunderbird was running in the background
fixed
Status bar messages displayed unlocalizedd folder names or IMAP mailbox names
fixed
New Folder dialog allowed invalid folder creation without a selected parent folder
fixed
New/unread messages in collapsed thread were not obvious enough
fixed
Invalidly signed unencrypted emails were indicated as worse than unsigned ones
fixed
Untagged messages were not working correctly with quick filter
fixed
Calendar/address book sections were shown in Account Hub when there were none
fixed
Shortcuts could be executed on background mail window while in Account Hub
fixed
Adding a Gmail account prompted for OAuth during auto config
fixed
New password-based Exchange accounts failed to save passwords in login manager
fixed
'Move Message to' filter action was not logged
fixed
Unknown OAuth providers were not allowed during EWS manual config in AccountHub
fixed
Saved search in unified folder resulted in server error
fixed
EWS password prompt looped endlessly if the password was empty
fixed
Account Hub manual configuration flow for Exchange accounts was incorrect
fixed
CalDAV calendars that invited calendar alias did not give all response options
fixed
iCal imports misread unknown timezones as GMT, creating events at wrong times
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 New
new
Add mail.openpgp.load_untested_gpgme_version to load untested GPGME version
What’s Fixed
fixed
CalDAV calendar with multiple addresses could crash on multi-attendee invites
