Latest version of Thunderbird released

Thunderbird 150.0.2​

Security fixes

Thunderbird 151.0​

What's new

Enable Thundermail OAuth sign-in with account auto-configuration
Enable users to override OAuth provider details for EWS accounts
Tasks can be sorted by created or modified date

Changed

Reinstated default application check when Thunderbird starts
OpenPGP public key no longer attached by default in signed-only messages

What’s Fixed

Thunderbird could crash when processing message headers
Thunderbird could crash on startup
Calendar view tabs were not properly keyboard accessible
Thunderbird could crash when processing new incoming messages
On macOS, dragging attachments out of Thunderbird created multiple copies
Cancelling a newsgroup posting was not possible
Some IMAP emails showed current time instead of correct received date
Search result count was missing when using 'Find in Message' or Ctrl+F
Search results showed older irrelevant emails before newer exact matches
Reply with selected text lost formatting for HTML messages containing
Multipart/related attachments were not preserved when editing or forwarding
Forwarded malformed MIME email had empty body and extra attachment
OWL add-on description was not visible in Account Hub for non-en-US locales
Account Hub prompted for password after OAuth login, causing Outlook setup failure
Auto-discovered Account Hub values were not preserved for manual editing
Account Hub links for encryption and signature opened the wrong account
Virtual folders did not update correctly for filtered POP3 messages
Thunderbird could crash in spam filtering
Using thunderbird -compose with double quotes made last email address invalid
With auto-mark-read disabled, large mail still marked as read during load delay
It was not possible to create date-only all-day tasks
Task context menu (right-click) had several disabled menu items
'Current Tasks' view showed past and finished tasks instead of only unfinished
Visual and UX improvements
Security fixes

I notice the updates come close to the Firefox updates as well. Almost synchronized, almost...

Thunderbird 151.0.1​

Fixed​

Forwarding/Redirecting Exchange messages failed with NS_ERROR_OUT_OF_MEMORY

This latest version broke dark themes...

Josey Wales said:

Thunderbird Eclipse 152.0

Click to expand...

Version 152.0 | Released June 16, 2026​

What's New ​

SecurityDevices enabled in enterprise policies

One-click account setup for Thundermail accounts

What’s Changed​

Use 'Add' instead of 'New' for account, calendar, address book creation buttons
GMail OAuth updated to use PKCE
Mail server hostname is also checked when detecting address books and calendars
Updated about:rights to replace local with hosted url
'Hide completed tasks' now also hides cancelled tasks

What’s Fixed​

New mail alerts appeared on wrong monitor in three-monitor setup
Spam messages triggered new mail notifications before being moved to Spam folder
Filtered IMAP or NNTP subscriptions were lost after closing Subscribe dialog
'Download Headers' dialog for newsgroups failed to open
Messages nested deeper than 255 levels disappeared from threading view
Performing Delete followed by Undo on thread parent message could corrupt view
Single messages still appeared collapsible after thread members were deleted
Updated threads remained misordered until folder refresh or resort
Non-threaded subject sorting separated 'RE:' replies from original messages
BCC recipients were included in signed email headers
Performance issue when decrypting encrypted messages
Filter search on Body missed draft messages containing German umlauts
Thunderbird could crash during local message search
Blocked file warning showed without 'Unblock File' button in compose window
Forwarding/Redirecting Exchange messages failed with NS_ERROR_OUT_OF_MEMORY
Compose window closed early and send progress dialog hung after NNTP failure
Compose window stayed open after sending when mailnews.sendInBackground set
Microsoft OAuth2 failed when HTTPS localhost redirect was not intercepted
Pasting contact photos stopped working when photo button had focus
Filter dialog lacked focus ring and had poorly distinguishable buttons
Subfolder kept stale accessibility unread count after unread messages were deleted
'Edit as New Message' and inline 'Forward' not possible with PGP-signed messages
Various MIME improvements
EWS messages could go missing from folder view
IMAP "Show only subscribed folders" could not be changed without restart
Unable to delete more than 1000 messages at a time on Microsoft 365
EWS folders in Trash were moved to Trash again instead of being hard deleted
IMAP notifications repeated for emails read on another device after sleep wake
POP3 deadlocked when server went silent without closing socket
Calendar acceptance no longer distinguished between single occurrence and series
Transparent popups on macOS made calendar event editing difficult
Duplicate attendees were added to invitations instead of being filtered out
Task percentage complete was not preserved separately from status in tooltips
Visual and UX improvements

Security fixes

Thunderbird 152.0.1 Released June 30, 2026​

Fixed​

Reply All button was missing for some EWS messages with multiple recipients

Security fixes