Thunderbird Updates & Release Notes

Follow

18 updates curated from 1 source by the Releasebot Team. Last updated: Aug 4, 2026

Get this feed:
  • Aug 4, 2026
    • Date parsed from source:
      Aug 4, 2026
    • First seen by Releasebot:
      Aug 4, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 153.0.2esr

    Thunderbird restores Yahoo sign-in flow and fixes an Edit Calendar dialog title issue to improve reliability.

    Changed

    Restored previous Yahoo sign-in flow to improve login reliability

    Fixed

    Edit Calendar dialog opened without a window title

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

    Original source
  • Jul 28, 2026
    • Date parsed from source:
      Jul 28, 2026
    • First seen by Releasebot:
      Jul 28, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 153.0.1

    Thunderbird fixes unreadable New Message and New Event buttons in RTL locales and resolves OpenPGP sending failures.

    Fixed

    • New Message and New Event buttons were unreadable in right-to-left locales
    • OpenPGP sending failed when an accepted key lacked a valid encryption subkey

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

    Original source
  • All of your release notes in one feed

    Join Releasebot and get updates from Mozilla and hundreds of other software products.

    Create account
  • July 2026
    • No date parsed from source.
    • First seen by Releasebot:
      Jul 17, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 153.0

    Thunderbird adds smarter account and OAuth handling, broader EWS and IMAP fixes, and improved calendar and attachment behavior. This release also brings security updates, crash fixes, OpenPGP and S/MIME improvements, and a range of usability and sync refinements.

    What’s New

    Unified folders now display account color indicator with account name tooltip

    OAuth login for mail accounts now opens in default web browser

    Thundermail services can now be used without installing an add-on

    OAuth responses now verify issuer fields and reject missing required issuers

    Changed

    Removed Odnoklassniki chat setup and directed users to XMPP configuration

    Fixed

    Ctrl+S did not save PDF attachments opened in Thunderbird tabs

    TLS errors incorrectly reported all unknown failures as untrusted certificates

    Thunderbird could crash during shutdown

    Thunderbird could crash when copying an empty list of messages

    New mail alerts incorrectly sized or positioned on some multi-monitor setups

    Old IMAP profile migration deleted INBOX and other mailbox files

    Space bar did not scroll in PDF attachments opened from emails

    'Search Messages' shortcut (Ctrl+Shift+F) failed in standalone message window

    Folder location widget used non-localised name

    Empty confirmation dialog when more messages opened in tabs than mailnews.open_tab_warning

    Removing tags from IMAP messages could fail and tags reappeared after refresh

    Folder pane could not be horizontally resized in additional 3-pane tabs

    Global search failed to display inaccessible messages found in local folders

    Numeric subfolders were sorted alphabetically instead of naturally

    Virtual folder folder-picker showed unlabeled IM account as selectable folder

    Virtual folders failed to preserve the online search setting

    Apple Mail OpenPGP emails failed to decrypt due to hidden recipient key ID

    OpenPGP import of public key with experimental packets failed with unclear error

    Performance issue when decrypting encrypted messages

    Opening messages with OpenPGP keys was slow and blocked the UI for large keyrings

    OpenPGP key refresh failed when fingerprint lookup returned multiple results

    Invalid S/MIME encryption certificate caused misleading send errors

    Esc cleared quick filter pin after changing folder

    Dragging email address between compose windows failed to add recipients

    Thunderbird could crash when using Find and Replace All

    Sending Message dialog got stuck on "Filter complete." after successful send

    Compose with PDF attachments opened PDFs instead of creating a new email

    Attachments opened via -compose on Windows could use incorrect filenames

    Ctrl+Enter opened attachment instead of sending the message

    Compose window remained open when delayed sending was enabled

    Account hub showed connection security instead of actual authentication method

    Account Hub GSSAPI autoconfiguration incorrectly prompted for a password

    New identity dialog lacked reply-matching and end-to-end encryption settings

    Account Hub manual EWS setup lacked OAuth authentication option

    Thunderbird could fail to shut down cleanly during active OAuth requests

    Account Hub kept OAuth selected after changing to hostname without OAuth support

    Account Hub showed a false error when returning from EWS manual configuration

    Account Hub autodetect wrongly prompted for a password when auth was unavailable

    QR exports with SMTP passwords generated invalid data for Thunderbird for Android

    Message Filters 'Run Now' button remained disabled after filter run or mail check

    Redirected CardDAV URLs resolved relative URLs against the wrong host

    Thunderbird could crash when completing folder copy/move

    Forwarding some Apple Mail messages incorrectly attached inline text as a file

    Auto-compaction could corrupt database and cause crashes during syncs

    NNTP server with invalid TLS certificate could not be added to certificate exceptions

    Sent message in EWS account showed message as unread in the sent items folder

    EWS NTLM authentication triggered login failures despite successful syncs

    Saving inline Exchange images used incorrect filenames and file types

    Cancelled message send could not be retried and hung with SMTP timeout errors

    EWS folders failed to show new mail notifications until the folder was selected

    Corrupted NNTP account data caused excessive memory use and startup crash

    Multiple selected IMAP folders could not be moved or deleted together

    Non-Latin IMAP keywords were lowercased and encoded incorrectly as MUTF-7

    Message tags were lost when moving folder from local folder to IMAP folder

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

    EWS users could not permanently delete individual Trash messages

    Removing a chat account threw an exception and failed to clear the UI

    Primary Password policy was detected but not enforced for saved account passwords

    Copying one recurring event occurrence failed to set the date when pasted

    Calendar invites were incorrectly marked processed after calendar sync completed

    ICS event comments were not displayed in Thunderbird event details

    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

    Original source
  • July 2026
    • No date parsed from source.
    • First seen by Releasebot:
      Jul 14, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 153.0esr

    Thunderbird adds a broad round of productivity, security, and usability upgrades, including visual signatures for PDF attachments, better OpenPGP and OAuth support, Exchange and Thundermail account setup, touch-friendly calendar views, folder and mail UI improvements, and many stability fixes.

    What’s New

    Visual signatures can be added to PDF attachments opened in Thunderbird

    'Copy Message Link' and 'Copy News Link' added to header pane 'More actions'

    Accessiblity is improved in various tree views

    Added 'Archive' action to mail notifications

    Add "Show Full Path" folder pane option for compact view modes

    Unified folders now display account color indicator with account name tooltip

    Folder copy enabled within mail server accounts and local folders

    'Reset Folder Order' option added to folder pane to reset custom folder sorting

    Add `mail.useLocalizedFolderNames' to toggle special folder name localization

    'Favorites' added as destination for 'Move To' and 'File' buttons

    Added Proton Mail key server and WKD key discovery for Proton domains

    Composer now shows a warning if user's configured OpenPGP key expires soon

    Enabled configuration of preferred OpenPGP keyserver via the UI

    Add mail.openpgp.load_untested_gpgme_version to load untested GPGME version

    Added support for generating Unobtrusive Signatures (OpenPGP)

    Implemented option to show only messages without any tag

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

    SecurityDevices enabled in enterprise policies

    Enable support for DNS over HTTPS

    OAuth login for mail accounts now opens in default web browser

    Thundermail services can now be used without installing an add-on

    OAuth responses now verify issuer fields and reject missing required issuers

    Enable the "Sign in with Thundermail" button in Account Hub

    Account hub is opened on the first run of Thunderbird

    Account Hub email manual config option added

    Enable Thundermail OAuth sign-in with account auto-configuration

    One-click account setup for Thundermail accounts

    Address book cards can be copied to the clipboard as vCard

    Enable exporting selected address book cards

    Custom Accent Color can be chosen in Appearance Settings

    Enable support for Microsoft Exchange via Exchange Web Services

    Calendar month/multiweek views are now scrollable with touch screen

    Tasks can be sorted by created or modified date

    PDF pages can be reorganized directly in the PDF viewer

    Changed

    'Copy Message Location' removed from mail context menu

    Read folders are now removed from Unread Folders view

    Special folders are now localized based on a restricted set of names

    OpenPGP public key no longer attached by default in signed-only messages

    Address books are now created in Account Hub

    Yahoo, AT&T, AOL accounts migrated to OAuth 2.0 with PKCE for improved security

    GMail OAuth updated to use PKCE

    Skype has been retired and therefore dropped from Address book IM selection

    Removed pref default_supports_diskspace.{HOST}

    Removed pref default_offline_support_level.{HOST}

    Removed Odnoklassniki chat setup and directed users to XMPP configuration

    Use of the string "Junk" has been replaced with "Spam"

    Updated about:rights to replace local with hosted url

    Stop shipping 32-bit Linux x86 binaries

    'Hide completed tasks' now also hides cancelled tasks

    Fixed

    Thunderbird could crash when parsing message state

    The English string for the Angry emoji was incorrectly named as the Yell emoji

    Notification sounds did not respect operating system's do-not-disturb mode

    Non-English localized Thunderbird created English special folders on first start

    Copying text from some error alerts was not possible

    Fastmail CalDAV app password access failed due to forced OAuth regression

    Thunderbird could crash in server subscription logic

    Could not distinguish folders with same name in 'Recent Destinations' and 'Favorites'

    Donation banner stole focus when Thunderbird was running in the background

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

    Thunderbird could crash when processing new incoming messages

    Spam messages triggered new mail notifications before being moved to Spam folder

    Web pages with bad certificates displayed as blank

    Memory leak after opening New Window from folder pane context menu

    Importing a vCard only displayed VCF files in the file picker

    Calendar view tabs were not properly keyboard accessible

    Ctrl+S did not save PDF attachments opened in Thunderbird tabs

    TLS errors incorrectly reported all unknown failures as untrusted certificates

    Thunderbird could crash when copying an empty list of messages

    Incorrect roaming data directory caused regression on Windows and macOS

    Changing to new drafts folder and then back did not correctly restore the folder

    Message headers were re-downloaded at every startup

    Old IMAP profile migration deleted INBOX and other mailbox files

    'Search Messages...' dialog could not be opened outside the email tab

    Option did not exist to create new address book under File -> New

    Newly created folder was missing under "Recent" when moving a message

    Could not compose new message if the folder pane was empty

    'Delete' was missing from context menu when multiple IMAP folders were selected

    Compacting multiple folders failed and did not compact

    Shift-click for 'Edit' button in drafts header view did not work

    "Replace All" in Compose did not update plain text until dialog closed

    Status bar messages displayed unlocalized folder names or IMAP mailbox names

    Saved email filenames were not not always cross-platform safe

    Space bar did not scroll in PDF attachments opened from emails

    Folder location widget used non-localised name

    Empty confirmation dialog when more messages opened in tabs than mailnews.open_tab_warning

    Removing tags from IMAP messages could fail and tags reappeared after refresh

    Toggling dark message mode did not restore focus and scroll position

    'Show remote content' did not display remote content for EML message

    Emoji sequences were not properly handled in subject lines

    'Delete' button in unified toolbar could delete attachments instead of message

    "Repair text encoding" could duplicate recipient and attachments

    Some IMAP emails showed current time instead of correct received date

    Deleting a single message in folder using 'Group by Sort' failed after CTRL+A

    New newsgroups were not added in alphabetical order by default

    Sorting by threads only brought threads with unread top messages to the top

    News message marked read after NNTP error prevented retrieval from server

    'Recent destinations' submenu was not sorted by time of modification

    Account column could display incorrect account name

    'Tag' submenu of mail context menu could be populated incorrectly

    Unified archive subfolders could show wrong names and no messages

    Moving saved search/virtual folder under IMAP could fail

    New Folder dialog allowed invalid folder creation without a selected parent folder

    New/unread messages in collapsed thread were not obvious enough

    Pressing Delete on Trash folder could remove it without confirmation

    Renaming of a 'unified folder' created a duplicate

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

    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

    Global search failed to display inaccessible messages found in local folders

    Numeric subfolders were sorted alphabetically instead of naturally

    Virtual folder folder-picker showed unlabeled IM account as selectable folder

    Some folders showed new mail count prior to receiving mail

    Menu Bar -> View contained duplicate accelerator keys

    Unified toolbar Spam button did not switch to "Not Spam" when spam message selected

    Warning was not logged if mail.openpgp.alias_rules_file file did not exist

    Not all headers were signed when creating digitally signed OpenPGP email

    When configuring external GnuPG, user was not promted to import public key

    "Open and Show" for OpenPGP-signed message (.eml) did not work

    Invalidly signed unencrypted emails were indicated as worse than unsigned ones

    Reason for revoked certificate was not shown

    Apple Mail OpenPGP emails failed to decrypt due to hidden recipient key ID

    OpenPGP import of public key with experimental packets failed with unclear error

    Opening messages with OpenPGP keys was slow and blocked the UI for large keyrings

    OpenPGP key refresh failed when fingerprint lookup returned multiple results

    Encrypted Gmail CSE emails with outer opaque S/MIME were not readable

    Invalid S/MIME encryption certificate caused misleading send errors

    "Search Messages" search did not finish due to unparsable local folders

    Search results showed older irrelevant emails before newer exact matches

    Filter search on Body missed draft messages containing German umlauts

    Esc cleared quick filter pin after changing folder

    Thunderbird could crash during local message search

    Replying could fail with mailnews.reply_quoting_selection.multi_word set false

    Drag-drop of unselected contact inserted wrong or no email address

    Changing identity in compose window caused modified draft not to be saved

    Shift-click 'Compose Message To' on 'mailto' link did not open in plain text

    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

    Message compose window was removed from Task Bar after saving as draft or template

    Dragging email address between compose windows failed to add recipients

    Thunderbird could crash when using Find and Replace All

    Multiple saves while using 'Options' -> 'Send a Copy' resulted in multiple copies

    Search for "Attachment" in Settings menu did not find "Files and Attachments"

    Add-on account creation did not work with Account Hub

    Owl install did not show link to website in Account Hub

    Username field did not appear in Account Hub when exchange authentication failed

    Account Hub advanced config setup did not include default outgoing config

    Disabled inputs could be toggled in Account Hub address book

    Users could not disable spinning overlay in Account Hub for email

    Account Hub local address book creation could continue with blank name

    Account Hub email success messages were not always accurate about config source

    Calendar/address book sections were shown in Account Hub when there were none

    New password-based Exchange accounts failed to save passwords in login manager

    Account hub showed connection security instead of actual authentication method

    New identity dialog lacked reply-matching and end-to-end encryption settings

    Thunderbird could fail to shut down cleanly during active OAuth requests

    Account Hub kept OAuth selected after changing to hostname without OAuth support

    Account Hub autodetect wrongly prompted for a password when auth was unavailable

    Interrupted external OAuth2 setup required restarting Thunderbird

    The default account could be reset after restart if uninitialized

    Virtual folders did not update correctly for filtered POP3 messages

    'Copy Message to' action in a newsgroup filter did not work

    Thunderbird could crash while importing mail thread

    Thunderbird did not clearly fail when importing profile from a bad source

    Thunderbird could not import profile located at the top level of zip file

    'Any Number' was unavailable in address book search with 'Match all of the following'

    Contact not found in Advanced Address Book Search if phone number had a period

    Thunderbird did not display contact photos in WebP format from CardDAV servers

    Opening a vCard (.vcf) from file manager or CLI did not work in some cases

    Redirected CardDAV URLs resolved relative URLs against the wrong host

    Installations from Microsoft Store did not open when clicking 'mailto:' links

    Windows new message notification click did not bring Thunderbird to foreground

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

    Using thunderbird -compose with double quotes made last email address invalid

    Clicking the backspace icon in the quick filter field cleared the input field

    Subfolder kept stale accessibility unread count after unread messages were deleted

    Moving virtual folder within maildir based IMAP or local folder could fail

    Thunderbird could crash when completing folder copy/move

    'Edit as New Message' and inline 'Forward' not possible with PGP-signed messages

    Various MIME improvements

    Forwarding some Apple Mail messages incorrectly attached inline text as a file

    Thunderbird could crash when marking all messages as read

    Auto-compaction could corrupt database and cause crashes during syncs

    'news:' URIs without specific server had incorrect format displayed in status bar

    'Mark' -> 'All Read' affected newsgroup messages that had not been fetched yet

    Thunderbird could not reconnect to newsgroups after connection loss until restarted

    Sending a newsgroup post appeared successful when it had actually failed

    Saving a new draft retained superceded version

    Thunderbird hung when auto-checking multiple accounts for new messages

    Spam not checked with mail.server.default.check_all_folders_for_new on

    Startup could be slow with large number of folders not using subscriptions

    Saved search in unified folder resulted in server error

    Thunderbird did not report refused POP3 connection

    Remove message body retention policy was not functional

    POP3 could stop downloading mail until restart

    With auto-mark-read disabled, large mail still marked as read during load delay

    IMAP "Show only subscribed folders" could not be changed without restart

    POP3 deadlocked when server went silent without closing socket

    Thunderbird could crash when mail folder was renamed or moved

    NNTP server with invalid TLS certificate could not be added to certificate exceptions

    Cancelled message send could not be retried and hung with SMTP timeout errors

    Corrupted NNTP account data caused excessive memory use and startup crash

    Multiple selected IMAP folders could not be moved or deleted together

    Non-Latin IMAP keywords were lowercased and encoded incorrectly as MUTF-7

    Message tags were lost when moving folder from local folder to IMAP folder

    Removing a chat account threw an exception and failed to clear the UI

    Enterprise policy use not indicated in about:preferences with link to about:policies

    Language field in settings was empty after restart in Troubleshoot Mode

    Primary Password policy was detected but not enforced for saved account passwords

    Archived RSS feed messages were sent to the archive folder of default identity

    Broken feed icon could prevent updating of feeds

    Task reminders could fail for tasks without end dates or with shifted due dates

    Calendar did not alert user for connection issues

    Copying one recurring event occurrence failed to set the date when pasted

    Could not copy an event in multiweek or month view by drag-and-drop

    Duplicate attendees were added to invitations instead of being filtered out

    Calendar discovery with certificate error displayed multiple exceptions

    It was not possible to create date-only all-day tasks

    Task percentage complete was not preserved separately from status in tooltips

    Calendar invites were incorrectly marked processed after calendar sync completed

    ICS event comments were not displayed in Thunderbird event details

    Dismissed Gmail calendar reminder did nothing and item stayed visible

    iCal imports misread unknown timezones as GMT, creating events at wrong times

    Could not export local calendar as HTML

    Cancelled filter edit dialog closed the message filter dialog

    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

    Original source
  • June 2026
    • No date parsed from source.
    • First seen by Releasebot:
      Jun 27, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 152.0.1

    Thunderbird fixes a missing Reply All button for some EWS messages and includes security fixes.

    Fixed

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

    Security fixes

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

    Original source
  • Similar to Thunderbird with recent updates:

  • Jun 16, 2026
    • Date parsed from source:
      Jun 16, 2026
    • First seen by Releasebot:
      Jun 16, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 152.0

    Thunderbird adds enterprise policy security device support, one-click Thundermail setup, and a broad round of mail and calendar fixes plus performance, OAuth, MIME, and usability improvements.

    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

    Original source
  • May 26, 2026
    • Date parsed from source:
      May 26, 2026
    • First seen by Releasebot:
      May 27, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 151.0.1

    Thunderbird fixes Forwarding and Redirecting Exchange messages that failed with NS_ERROR_OUT_OF_MEMORY.

    Fixed

    Forwarding/Redirecting Exchange messages failed with NS_ERROR_OUT_OF_MEMORY

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

    Original source
  • May 19, 2026
    • Date parsed from source:
      May 19, 2026
    • First seen by Releasebot:
      May 16, 2026
    • Modified by Releasebot:
      May 19, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 151.0

    Thunderbird ships a broad update with Thundermail OAuth sign-in, better Account Hub and EWS setup, task sorting and calendar fixes, plus reliability and security improvements. This release also improves message handling, search, IMAP, OpenPGP, and accessibility.

    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

    Original source
  • May 8, 2026
    • Date parsed from source:
      May 8, 2026
    • First seen by Releasebot:
      May 9, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 140.10.2esr

    Thunderbird fixes security issues and invites users to share feedback or file bugs.

    Fixed

    Security fixes

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

    Original source
  • May 8, 2026
    • Date parsed from source:
      May 8, 2026
    • First seen by Releasebot:
      May 9, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 150.0.2

    Thunderbird fixes security issues and encourages users to share feedback or file bugs.

    Fixed

    Security fixes

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

    Original source
  • Apr 30, 2026
    • Date parsed from source:
      Apr 30, 2026
    • First seen by Releasebot:
      May 9, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 140.10.1esr

    Thunderbird fixes security issues in a routine update.

    Fixed

    Security fixes

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

    Original source
  • Apr 30, 2026
    • Date parsed from source:
      Apr 30, 2026
    • First seen by Releasebot:
      May 9, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 150.0.1

    Thunderbird fixes a crash when processing message headers and includes security fixes.

    Fixed

    Thunderbird could crash when processing message headers

    Security fixes

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

    Original source
  • Apr 21, 2026
    • Date parsed from source:
      Apr 21, 2026
    • First seen by Releasebot:
      May 9, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 140.10.0esr

    Thunderbird fixes newly translated strings and includes security fixes.

    Fixed

    Newly translated strings were not available in Thunderbird

    Security fixes

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

    Original source
  • Apr 21, 2026
    • Date parsed from source:
      Apr 21, 2026
    • First seen by Releasebot:
      May 9, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 150.0

    Thunderbird adds better account setup, OpenPGP and S/MIME search support, touch-friendly calendar scrolling, PDF page reordering, and customizable appearance options. It also brings accessibility, stability, and security fixes across mail, folders, Exchange, and Microsoft Store installs.

    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

    Original source
  • Apr 7, 2026
    • Date parsed from source:
      Apr 7, 2026
    • First seen by Releasebot:
      May 9, 2026
    Mozilla logo

    Thunderbird by Mozilla

    Thunderbird 140.9.1esr

    Thunderbird fixes security issues and invites users to share feedback or file bugs.

    Fixed

    Security fixes

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

    Original source
Releasebot

Curated by the Releasebot team

Releasebot is an aggregator of official product update announcements from hundreds of software vendors and thousands of sources.

Our editorial process involves the manual review and audit of release notes procured with the help of automated systems.