Betterbird: Release Notes

Current Series: Betterbird 140

Betterbird 140 offers all the features and bug fixes mentioned in the feature table on the home page: Multi-line view, full account colours, attachments on top, complex search terms, regular expression search, search in encrypted messages, improved Windows and Linux system tray integration, and many more. This page contains features added during the 140 series. Check the release notes of the prior series for features that got added before the 140 series: 128 series, 115 series, 102 series, 91 series.

140.5.0esr-bb14 "latest build 3" (14 Nov 2025, in English for Windows only)

This version is not offered as an update. Changes will ship in the next release.

Fixed in this version:

NEW - Add boolean Gloda facets "Subject" and "Body" to filter messages what match on subject or body
NEW - Allow searching all folders of all mail accounts in "Search Messages" dialogue. Feed and news folders are excluded. - Bug 131438
FIXED - Non-ASCII search term values not processed correctly

Various minor fixes that Thunderbird isn't shipping yet in the 140 series:

Bug 1842514

140.5.0esr-bb14 (8 November 2025)

Based on Thunderbird 140.5.0esr, release notes.

Fixed in this version:

NEW - Preference mail.imap.allow_unsubscribe_noselect allows unsubscribing from \NOSELECT IMAP folders. This is useful for Protom Mail Bridge users who with to remove unneeded folders Labels and Folders from the folder pane. - GitHub #497
CHANGED - The "Recent Destinations" folder list shows folders again into which messages were recently moved. The Filter Editor still uses recently used folders.
FIXED - Placement of Betterbird-native new mail alert on wrong monitor. Preference mail.notification.show_on_app_screen not working correctly in some cases.
FIXED - Reinstated preference mail.folderpane.sumSubfolders - Bug 1852171
FIXED - Calendar scroll issue - Bug 1976182

Features and fixes exclusive to Betterbird (new in the 140 series):

CHANGED - The tooltip of the folder name in the message list header and the folder pane now shows the full folder path (140.4.0) - Bug 382977
CHANGED - File name sanitation has been unified for all platforms: /\:*? are replaced with underscore, " and < > are also replaced. (140.4.0)
FIXED - "Open Link in Browser" in the compose window caused an unnecessary prompt. For non-http(s) URLs, preference mail.external_protocol_requires_permission is now honoured. (140.4.0)
FIXED - Issue in WebExtension API setQuickFilter() leading to incompatibility with add-on "quickfilter-kbd" (140.4.0)
FIXED - Issue when detaching attachment (140.4.0) - GitHub #489
NEW - Mark button on the unified toolbar now has the junk options also present on the context menu in the message list (140.3.1)
CHANGED - Catch-all processing now also applied to forwarding of a message (inline or one message as attachment) and to "reply to self" (140.3.1)
CHANGED - The recent folder list now shows most recently used (visited or modified) folders (MRU), not most recently modified folders (MRM) (140.3.1)
FIXED - Mitigate random flashing of Betterbird-native new mail alert in top left corner of screen. If you have a dual-monitor setup and native alerts are now displayed on the right monitor, please read this blog post.
FIXED - Editing headers or rethreading in a local folder with maildir storage doubled up the message (140.3.1) - GitHub #485
FIXED - Editing the subject of a message in an IMAP folder sometimes didn't get reflected correctly in the message list (140.3.1) - Bug 1990129
FIXED - Preference mail.threadpane.full_row_color had no effect any more (140.3.1)
FIXED - OWL-based default account removed as default after restart (140.3.1) - GitHub #488
FIXED - "Junk" button didn't change to "No Junk" when junk message is selected (140.3.1) - Bug 1831713
CHANGED - When the master password isn't entered correctly, the application will be closed (140.3.0) - Bug 1566458
CHANGED - Always show missed reminders for future events to avoid missing reminders while Betterbird is closed (140.3.0) - Bug 1988288
CHANGED - Withdrawn feature: Choice in View > Message Body As no longer distinguishes between mail/news messages and RSS feeds. The feature wasn't stable and led to the wrong render preference being applied. (140.3.0)
FIXED - Some oversized images didn't show the zoom-in/out cursor (if their CSS set its own cursor) (140.3.0)
FIXED - Font and background colour not correct for plain text composition in dark mode (140.3.0) - Bug 1976738
FIXED - Sizing issues of OpenPGP key import info panel when may keys or keys with long user names are imported (140.3.0) - Bug 1958478
FIXED - IMAP trash not emptied on exit, mostly affected are GMX users (140.2.1) - Bug 1975147
FIXED - Choice in View > Message Body As not persisted (140.2.1) - GitHub #481
FIXED - Icon in Quick Filter Bar feedback not showing (140.2.1)
CHANGED - Default view restored to "Table View". Betterbird 140.2.0-bb9 erroneously shipped with "Cards View" as default. (140.2.1)
CHANGED - Switched off new experimental so-called Account Hub for the creation of new mail accounts. It is still too buggy. (140.2.0)
CHANGED - Set some gfx.font_rendering.cleartype_params. preferences for better font rendering on Windows (140.2.0) - Bug 1946024


Fixes in early preview releases before 140.2.0:
FIXED - Add-on compatibility issue
NEW - Preference mail.activity.managerInTab to disable opening the Activity Manager in a tab
NEW - Preference mail.thread.rethreading.allowDragAndDrop to disable (accidental) rethreading via drag and drop
FIXED - Incorrect indentation of correspondents column in multi-line view
MITIGATED - Updating a CardDAV address book can lead to data loss. This is now mitigated by showing a warning message - Bug 1980005 Bug 1980024
For details in the following feed reader improvements, also note this section.
NEW - Support JSON feeds - Bug 1678721
NEW - Optionally store updated articles for Atom and JSON feeds - Bug 270275 Bug 1871741 Bug 1939390
NEW - Optionally store of the feed article web page with the message, preference rss.show.feed-webpage-archive controls the display: 0: archive not used, 1 (default): archive used when offline or no network, 2: archive always used - Bug 308436
NEW - Archive option for feed accounts. Messages in a feed account are archived according to account settings rather than default identity settings. - Bug 1360858
NEW - Horizontal view for users with vertical screen setup - Bug 1964119
NEW - Header pane button to easily show message headers, configurable via preference mail.messageEditor.showCustomHeaders. See this paragraph for details.
NEW - Allow filters to run on non-inbox IMAP folders that receive new messages on the server - Bug 294632
CHANGED - The Spanish localisation now uses the es-ES locale
CHANGED - The German installer for Windows is now localised
FIXED - User agent string not correct causing problem with add-on search on ATN
FIXED - Unnecessary scrollbar in the thread pane in table view
FIXED - Binaries weren't signed with a time stamp which led to problems in Windows 11. Refer to this section for details.
FIXED - Getting Involved link in About box not working
FIXED - Link underlying with preference layout.css.always_underline_links not working - Bug 1970689
FIXED - Messages moved from POP Inbox via filter remain in Inbox and reappear after Repair. Compact not always removes them. (New fix in 140 series) - Bug 1890253
FIXED - Folders which were manually sorted/reordered in BB 128 will maintain the order in BB 140

Various minor fixes that Thunderbird isn't shipping yet in the 140 series:

Bug 377487/1977953 Bug 541744 Bug 617287 Bug 617855 Bug 694780 Bug 1667865 Bug 1829728 Bug 1829748 Bug 1851875 Bug 1853912 Bug 1900708 Bug 1901338 Bug 1912195 Bug 1921406 Bug 1947052 Bug 1951824 Bug 1962868 Bug 1966737 Bug 1968915 Bug 1972710 Bug 1973658 Bug 1976327 Bug 1976738 Bug 1976900 Bug 1977042 Bug 1977051 Bug 1977204 Bug 1977321 Bug 1977461 Bug 1978682 Bug 1979551 Bug 1979567 Bug 1979618 Bug 1981322 Bug 1982353 Bug 1983993 Bug 1984376 Bug 1984894 Bug 1985033 Bug 1985610 Bug 1986092 Bug 1986289 Bug 1986428 Bug 1986558 Bug 1986642 Bug 1987834 Bug 1988230 Bug 1988558 Bug 1988607 Bug 1990129 Bug 1991417 Bug 1992351 Bug 1995417 Bug 1995926 Bug 1997914


Previous release notes for the 128 series
Previous release notes for the 115 series
Previous release notes for the 102 series
Previous release notes for the 91 series