Thunderbird Desktop
Version 152.0 | Released June 16, 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.
System Requirements: Details
- Windows: Windows 10 or later
- Mac: macOS 10.15 or later
- Linux: GTK+ 3.14 or higher
What’s New
new
SecurityDevices enabled in enterprise policies
new
One-click account setup for Thundermail accounts
What’s Changed
changed
Use 'Add' instead of 'New' for account, calendar, address book creation buttons
changed
GMail OAuth updated to use PKCE
changed
Mail server hostname also checked when detecting address books and calendars
changed
Updated about:rights to replace local with hosted url
changed
'Hide completed tasks' now also hides cancelled tasks
What’s Fixed
fixed
New mail alerts appeared on wrong monitor in three-monitor setup
fixed
Spam messages triggered new mail notifications before being moved to Spam folder
fixed
Filtered IMAP or NNTP subscriptions were lost after closing Subscribe dialog
fixed
'Download Headers' dialog for newsgroups failed to open
fixed
Messages nested deeper than 255 levels disappeared from threading view
fixed
Performing Delete followed by Undo on thread parent message could corrupt view
fixed
Single messages still appeared collapsible after thread members were deleted
fixed
Updated threads remained misordered until folder refresh or resort
fixed
Non-threaded subject sorting separated 'RE:' replies from original messages
fixed
BCC recipients were included in signed email headers
fixed
Filter search on Body missed draft messages containing German umlauts
fixed
Thunderbird could crash during local message search
fixed
Blocked file warning showed without 'Unblock File' button in compose window
fixed
Forwarding/Redirecting Exchange messages failed with NS_ERROR_OUT_OF_MEMORY
fixed
Compose window closed early and send progress dialog hung after NNTP failure
fixed
Compose window stayed open after sending when mailnews.sendInBackground set
fixed
Microsoft OAuth2 failed when HTTPS localhost redirect was not intercepted
fixed
Pasting contact photos stopped working when photo button had focus
fixed
Filter dialog lacked focus ring and had poorly distinguishable buttons
fixed
Subfolder kept stale accessibility unread count after unread messages were deleted
fixed
'Edit as New Message' and inline 'Forward' not possible with PGP-signed messages
fixed
Various MIME improvements
fixed
EWS messages could go missing from folder view
fixed
IMAP "Show only subscribed folders" could not be changed without restart
fixed
Unable to delete more than 1000 messages at a time on Microsoft 365
fixed
EWS folders in Trash were moved to Trash again instead of being hard deleted
fixed
IMAP notifications repeated for emails read on another device after sleep wake
fixed
POP3 deadlocked when server went silent without closing socket
fixed
Calendar acceptance no longer distinguished between single occurrence and series
fixed
Transparent popups on macOS made calendar event editing difficult
fixed
Duplicate attendees were added to invitations instead of being filtered out
fixed
Task percentage complete was not preserved separately from status in tooltips
fixed
Visual and UX improvements
