Thunderbird Desktop
Version 160.0beta | Released October 26, 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 160 beta 2 released October 28, 2026.
System Requirements: Details
What’s New
new
Ctrl+A selects all filters in the Message Filters dialog
What’s Changed
changed
OAuth sign-in windows now explain when blocked cookies may prevent sign-in
changed
Office 365 account setup no longer automatically offers EWS configuration
What’s Fixed
fixed
The macOS Dock badge could omit unread counts with multiple accounts
fixed
Opening a window could cause Thunderbird to crash
fixed
POP3 and news messages with LF line endings could be parsed incorrectly
fixed
The option to create a mailing list was missing from File > New
fixed
Restoring toolbar defaults unexpectedly closed the customization dialog
fixed
Thunderbird did not warn before repairing folders with offline message storage
fixed
Dragging multiple selected folders moved only one folder
fixed
Renaming or moving folders could remove them from saved searches
fixed
Replies to saved messages could be blocked despite a valid Reply-To address
fixed
The spelling dictionary menu was empty in the Subject field
fixed
Edit as New Message did not work for some news messages
fixed
Address book setup returned to mail setup when no mail account existed
fixed
Exchange autodiscovery failed when redirected to another email address
fixed
Empty message filter conditions could cause incorrect matches
fixed
Address book filter conditions failed to match messages with missing addresses
fixed
Address book website fields incorrectly prefixed non-HTTP links with HTTPS
fixed
Some CardDAV contacts with multiline street addresses appeared empty
fixed
CardDAV contacts were saved in a format unsupported by some servers
fixed
Photos saved in vCard 3.0 contacts could fail to appear in other clients
fixed
Processing some sender addresses could freeze new mail notifications
fixed
IMAP retention settings could delete newer messages instead of older ones
fixed
Message database updates could cause Thunderbird to crash
fixed
IMAP namespace root folders could be missing or have incorrect permissions
fixed
Graph account setup failed for tenants without a SharePoint license
fixed
Delete Event remained enabled for read-only calendars in the Today Pane
fixed
Attendance options were missing for some recurring event series
fixed
The task list stopped updating after toolbar customization
fixed
CalDAV reminders could not be dismissed or snoozed
fixed
Some webcal calendar subscriptions were incorrectly blocked
fixed
Invalid ICS calendar files could be overwritten when events were changed
fixed
Visual and UX improvements
Fixed in beta 2
What’s Changed
changed
There are no Thunderbird changes requiring release notes in this release
