Thunderbird Updates & Release Notes

What’s New

SecurityDevices enabled in enterprise policies

One-click account setup for Thundermail accounts

Changed

Use 'Add' instead of 'New' for account, calendar, address book creation buttons

GMail OAuth updated to use PKCE

Hostname of mail server 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

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

As always, you’re encouraged to tell us what you think, ask for help, or file a bug in Bugzilla

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

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 </pre>
• 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

As always, you’re encouraged to tell us what you think, ask for help, or file a bug in Bugzilla

What’s New

'Recent Destinations' in General Settings now supports alphabetical sorting

Added support for generating Unobtrusive Signatures (OpenPGP)

Message body search enabled for OpenPGP and S/MIME encrypted messages

Account hub is opened on the first run of Thunderbird

Address book cards can be copied to the clipboard as vCard

Custom Accent Color can be chosen in Appearance Settings

Calendar month/multiweek views are now scrollable with touch screen

PDF pages can be reorganized directly in the PDF viewer

Changed

Flatpak beta app ID changed from org.mozilla.Thunderbird to org.mozilla.thunderbird

Fixed

Unknown command-line arguments passed to Thunderbird did not print warning

Thunderbird could crash when creating a folder

Saved email filenames were not not always cross-platform safe

Compose progress dialog used unlocalised folder name

Clicking on a folder in the folder pane did not always open folder

Could not scroll to message bottom or view all attachments in some cases

Accounts could be listed twice after adding new account

Account Hub manual configuration was missing OAuth2 option

Microsoft Store installs did not open when clicking 'news://' link or .eml file

Folder states were not exposed to screen readers in saved search properties

Mailbox name was not announced and message count was incorrect for screen readers

POP3 could stop downloading mail until restart

Exchange servers/clients caused memory leaks by holding mutual references

Authentication could fail for some exchange accounts

'Move to New Window' option for the calendar was disabled

Calendar view had date and time axes swapped

Visual and UX improvements

Security fixes

As always, you’re encouraged to tell us what you think, ask for help, or file a bug in Bugzilla