Thunderbird Desktop
Version 146.0beta | Released November 19, 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.
These notes apply to Thunderbird version 146 beta 3 released November 19, 2025.
System Requirements: Details
- Windows: Windows 10 or later
- Mac: macOS 10.15 or later
- Linux: GTK+ 3.14 or higher
What’s New
new
Enabled configuration of preferred OpenPGP keyserver via the UI
new
Added support for NTLM authentication for EWS
What’s Changed
changed
Existing logins are migrated to make use of more modern AES cryptography
What’s Fixed
fixed
Memory was not cleaned up after opening New Window from folder pane context menu
fixed
Thunderbird could crash in server subscription logic
fixed
Importing a vCard only displayed VCF files in the file picker
fixed
Could not distinguish folders with same name in 'Recent Destinations' and 'Favorites'
fixed
Could not compose new message if the folder pane was empty
fixed
'Delete' was missing from context menu when multiple IMAP folders were selected
fixed
'Delete' button in unified toolbar could delete attachments instead of message
fixed
'Recent destinations' submenu was not sorted by time of modification
fixed
Account column could display incorrect account name
fixed
'Tag' submenu of mail context menu could be populated incorrectly
fixed
Could not sign/encrypt (PGP) when using -compose and Thunderbird was not running
fixed
Account Hub email success messages were not always accurate about config source
fixed
Account Hub advanced config setup did not include default outgoing config
fixed
Account Hub local address book creation could continue with blank name
fixed
Detailed security exception dialog was not shown when adding certificate exception
fixed
The default account could be reset after restart if uninitialized
fixed
Opening a vCard (.vcf) from file manager or CLI did not work in some cases
fixed
Dragging attachments on macOS to folder or desktop no longer worked
fixed
EWS folder properties "Select this folder for offline use" did not work
fixed
Thunderbird could crash when mail folder was renamed or moved
fixed
Account Hub could fail when manually creating EWS account
fixed
'Offline' folder flag for EWS folders was reset on restart
fixed
'Open with' of Microsoft Office attachment did not mark file with MOTW label
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
