Thunderbird Desktop
Version 145.0beta | Released October 16, 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 145 beta 4 released November 3, 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
Enable support for DNS over HTTPS
new
Account Hub email manual config option added
new
Account Hub address book creation enabled by default for beta
new
Enable support for Microsoft Exchange via Exchange Web Services
What’s Changed
changed
Skype has been retired and therefore dropped from Address book IM selection
changed
Removed pref default_supports_diskspace.{HOST}
changed
Removed pref default_offline_support_level.{HOST}
changed
Use of the string "Junk" has been replaced with "Spam"
What’s Fixed
fixed
'Save All' attachments with same names overwrote existing files without warning
fixed
Message headers were re-downloaded at every startup
fixed
Could not drag and drop ICS file to Today Pane
fixed
'Show remote content' did not display remote content for EML message
fixed
Emoji sequences were not properly handled in subject lines
fixed
Unified toolbar Spam button did not switch to "Not Spam" when spam message selected
fixed
Upgrading Thunderbird hid the Menu bar
fixed
When configuring external GnuPG, user was not promted to import public key
fixed
Add-on account creation did not work with Account Hub
fixed
Owl install did not show link to website in Account Hub
fixed
Username field did not appear in Account Hub when exchange authentication failed
fixed
Disabled inputs could be toggled in Account Hub address book
fixed
Manual account setup in Account Hub defaulted Connection Security to None
fixed
Close button from Account Hub was not narrated
fixed
Account Hub email creation error notifications were not narrated
fixed
Users could not disable spinning overlay in Account Hub for email
fixed
Deleted account data remained in "Export to mobile device" menu
fixed
'Sent' and 'Spam' folders were not always created when setting up new IMAP accounts
fixed
Spam was not checked with mail.server.default.check_all_folders_for_new on
fixed
Upgrade from 128.x->140.x broke authentication for @att.net using Yahoo backend
fixed
Task reminders could fail for tasks without end dates or with shifted due dates
Fixed in beta 2
What’s New
new
Add manual configuration to EWS account creation
What’s Fixed
fixed
Message compose window could incorrectly disappear from Task Bar on Windows
fixed
Some third-party hosted accounts could not be created in Account Hub
fixed
EWS users were unable to empty trash
fixed
Thunderbird failed to download EWS message with multiple reply-to addresses
fixed
Marking EWS folder as read appeared to work but was ignored server-side
Fixed in beta 3
What’s Fixed
fixed
Servers lacking localization showed special folder names in server’s language
fixed
Thunderbird could crash during exchange address account setup
fixed
System messages could break message sync for EWS
fixed
EWS messages with missing sender email address failed to sync
Fixed in beta 4
What’s Fixed
fixed
Account Hub allowed keyboard shortcuts to be executed in background screen
fixed
Receiving an EWS CalendarItem caused errors and blocked later message downloads
fixed
Dark theme did not render correctly since 145.0b2
fixed
Thunderbird could crash during EWS folder operations
fixed
Moving or copying a folder to EWS did not include subfolders and their messages
