Thunderbird Desktop
Version 149.0beta | Released February 25, 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 149 beta 3 released March 11, 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 exporting selected address book cards
new
Starred EWS messages now persist across devices
What’s Changed
changed
Address books are now created in Account Hub
What’s Fixed
fixed
Shift-click for 'Edit' button in drafts header view did not work
fixed
"Replace All" in Compose did not update plain text until dialog closed
fixed
"Repair text encoding" could duplicate recipient and attachments
fixed
Pressing Delete on Trash folder could remove it without confirmation
fixed
Renaming of a 'unified folder' created a duplicate
fixed
Reason for revoked certificate was not shown
fixed
"Open and show" for OpenPGP signed message could fail if headers after content-type
fixed
Encrypted Gmail CSE emails with outer opaque S/MIME were not readable
fixed
"Generate and save a CSR file as... " no longer worked for S/MIME
fixed
Cancelled attachment reminder in compose did not return focus to message body
fixed
Thunderbird could crash while importing mail thread
fixed
LDAP authentication could result in defunct contact search
fixed
Unlabeled column visibility toggle button was not announced by screen readers
fixed
Could not save message to external file from EWS account
fixed
"After Sending" filters were not working correctly
fixed
Thunderbird did not report refused POP3 connection
fixed
EWS messages could fail to sync in some scenarios
fixed
Remove message body retention policy was not functional
fixed
Dismissed Gmail calendar reminder did nothing and item stayed visible
fixed
Could not export local calendar as HTML
fixed
Cancelled filter edit dialog closed the message filter dialog
fixed
Visual and UX improvements
Fixed in beta 2
What’s Fixed
fixed
Link colors were difficult to read in dark themes
fixed
Folder tree "new messages" star no longer displayed
Fixed in beta 3
What’s Fixed
fixed
Could not add message filter rule for new custom header in 149 beta
