Betterbird: Release Notes

Betterbird 115 offers all the features and bug fixes mentioned in the feature table on the home page: Multi-line view, complex search terms, regular expression search, search in encrypted messages, improved Windows and Linux system tray integration, and many more. Check the release notes of the 102 series for features added before the 115 series.

115.9.0-bb26 "latest build (3)" (26 March 2024, Build-ID 2024-03-26*, English for Windows only)

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

Fixed in this version:

FIXED - A combination of text filter, negated tag filter and more than one tag button selected/negated sometimes gave wrong results
CHANGED - Switched Windows system notifications to new Mozilla platform code to improve registering in the Windows Action Centre on Windows 11.

115.9.0-bb26 (19 March 2024)

Based on Thunderbird 115.9.0, release notes.

Fixed in this version:

CHANGED - "Quick Filter untagged messages" replaced with "Quick Filter button negation" (incl. untagged messages) - Bug 683809 Bug 744365 Note: A combination of text filter, negated tag filter and more than one tag button selected/negated may give wrong results.(fixed in latest build)
FIXED - Usage of add-on "Grammar Checker & Paraphraser – LanguageTool" prevented downgrade of message to plain text
FIXED - Linux-only: Better detection of Gnome desktop to avoid crash related to system tray notifications
FIXED - Subject sometimes not spell-checked - Bug 1884761
FIXED - Unexpected: There are non-ASCII characters in the local part of the recipient address <empty> and your server does not support SMTPUTF8. - Bug 1885285
FIXED again - Incorrect total new message count in system tray tooltip and Windows taskbar badge (inconsistent with sum of folder counts) in rare cases
FIXED - Setting prefs mail.addressDisplayAuthor and mail.addressDisplayRecipients had no effect on a new profile
FIXED - Re-established secondary sort by date in "Grouped by Sort" views - Bug 1873353

Fixed in Betterbird, not fixed in Thunderbird 115.9.0 yet:

Fixes provided by the Betterbird project and integrated into Thunderbird to be released later

FIXED - Left-over temporary directories pid-NNNN and other temporary files (fixed in 115.7.0) - Bug 1873950
FIXED - A sound was sometimes played for new feed messages even if disabled with pref mail.feed.play_sound. New prefs mail.feed.play_sound.type and mail.feed.play_sound.url to configure feed notification sounds if desired (fixed in 115.6.1) - Bug 1871493
FIXED - Undo/Redo not working on stand-alone message window (fixed in 115.3.2) - Bug 1855643
FIXED - Delivery status notification (DSN) request not working when "Send Later" is used (fixed in 115.3.0) - Bug 815638

Various minor fixes that Thunderbird isn't shipping yet:

Bug 522768 Bug 531319 Bug 956446 Bug 1368011 Bug 1427546 Bug 1520435 Bug 1678057 Bug 1799368 Bug 1811214 Bug 1812726 Bug 1823024 Bug 1833031 Bug 1837152 Bug 1843221 Bug 1847265 Bug 1851975 Bug 1854138 Bug 1859271 Bug 1861200 Bug 1862519 Bug 1862521 Bug 1862978 Bug 1863820 Bug 1865598 Bug 1867091 Bug 1868094 Bug 1868718 Bug 1870873 Bug 1873282 Bug 1873313 Bug 1873607 Bug 1874450 Bug 1875577 Bug 1876431 Bug 1876662 Bug 1877774 Bug 1877962 Bug 1880043 Bug 1881124 Bug 1884661

Features and fixes exclusive to Betterbird (new in the 115 series):

NEW - Editing of message headers. The Edit Headers menu item is found in the message toolbar More Actions menu. By default the message subject is editable, use pref mail.messageEditor.editableHeaders to allow for more headers. (fixed in 115.8.1)
NEW - Message rethreading via drag & drop or the keyboard. See this paragraph for details. (fixed in 115.8.1)
FIXED - The additional total count in the status bar not always updating when a folder is entered or threads are collapsed or expanded (fixed in 115.8.1)
FIXED - Issue when using Quick Filter Bar with untagged messages (was broken in 115.8.0) (fixed in 115.8.1)
NEW - Preference mail.threadpane.full_row_color to fully colour rows in multi-folder views (fixed in 115.8.0)
FIXED - Some glitches with the arrow alignment in the correspondents column in multi-line view (fixed in 115.8.0)
CHANGED - Row height in compact density increased by 10% (from 18 px to 20 px) in thread pane, folder pane, address book and account manager (fixed in 115.8.0)
FIXED - Linux-only: Crash on Gnome when using Wayland related to system tray notifications (fixed in 115.8.0) - GitHub #266
WITHDRAWN - Quick filter tag bar doesn't refresh when other quick filter conditions change (only in 115.8.0) - Bug 1830439
FIXED - Some issues when editing plaintext quotes, mostly disappearing empty lines. Improves rewrap somewhat. (fixed in 115.8.0) - Bug 1787577 Bug 1851951
FIXED - Some unneeded logging to the Error Console (fixed in 115.8.0)
CHANGED - When folder had manually reordered subfolders, new subfolders were added at the end. Now they are added semi-alphabetically. (fixed in 115.7.0)
CHANGED - The total count in the status bar will now show an additional lesser second count if threads are hidden or collapsed (fixed in 115.7.0)
CHANGED - Default column order: Unread indicator column now precedes subject column (fixed in 115.7.0)
CHANGED - Complex search terms: Disallow group start immediately following group start (fixed in 115.7.0) - GitHub #256
FIXED - Console errors related to Apple's CalDAV property X-APPLE-STRUCTURED-LOCATION (fixed in 115.7.0)
FIXED - Attached images not reliably scaled when attachments viewed inline (fixed in 115.7.0) - Bug 1875325
FIXED - "Open Link in Browser" in compose window via context menu not reliable (fixed in 115.7.0) - Bug 695142
FIXED - Wrong folder sometimes briefly displayed at startup impacting performance (fixed in 115.7.0) - Bug 1874557
FIXED - Incorrect total new message count in system tray tooltip and Windows taskbar badge (inconsistent with sum of folder counts) in rare cases (fixed in 115.7.0)
FIXED - Regular expression search in (non-existent) message headers delivering false positives (fixed in 115.7.0)
NEW - New preference mail.folderpane.expand_delay (fixed in 115.6.1)
NEW - Column indicators for secondary search and icon columns (fixed in 115.6.1) - Bug 323067
CHANGED - Regular expression matching in search terms now using ICU's regular expression matching rather than std::regex (fixed in 115.6.1)
CHANGED - Enhancements to the splitters in the compose window, can now all be operated via the keyboard (fixed in 115.6.1)
CHANGED - Duplicate results of global search originating from Gmail's "All Mail" folder no longer displayed in the result list (fixed in 115.6.1) - GitHub #224
FIXED - Add-on installation problem on some Linux distributions incl. the one shipping with Chrome OS (fixed in 115.6.1) - Bug 1829370
FIXED - Some issues when manually re-ordering folders of (localised) Gmail account or local trash folder (fixed in 115.6.1)
NEW - Account colours part 2 and 3: Message list (unified folders only) and Write/compose window (fixed in 115.6.0)
FIXED - Crash when entering an invalid regular expression into a filter search term (fixed in 115.6.0)
FIXED - Phantom rows and search problems relating to too many folders being searched. Should now work with up to 6144 folders. On Linux, increase ulimit -n according to the number of folders in the profile. (fixed in 115.6.0)
NEW - End-of-year Donation campaign: Betterbird will ask for a donation. This is only once per profile per year. (fixed in 115.5.2)
NEW - Account colours part 1: Account Manager and folder pane. (fixed in 115.5.2). Note: Color black (#000000) is interpreted as "no colour". The chosen colour is applied with 20% opacity.
NEW - More layouts: "Wide thread" (thread pane wide on top, folder and preview pane below), "Stacked" (folder pane and thread pane both on the left) (fixed in 115.5.2)
NEW - Attachment list on top in Write (compose) window
NEW - Make tabs session restore optional. Option to restore no tabs, system tabs or all tabs. (fixed in 115.5.2)- Bug 506526
CHANGED - Thread pane can now be collapsed to the height of one row (fixed in 115.5.2) - Bug 1855611
FIXED - Minimise to tray not working on Linux if attempted before tray icon shows for the first time (fixed in 115.5.2) - GitHub #227
NEW - Quick filter and folder search in S/MIME encrypted messages (fixed in 115.5.1)
FIXED - Global search in S/MIME encrypted messages not working (fixed in 115.5.1)
FIXED - Problem with manually sorting (ordering) IMAP folders in folder pane (fixed in 115.5.1)
FIXED - Empty "phantom" content tabs appearing after startup-up (fixed in 115.5.1)
RESTORED - Windows system notifications (fixed in 115.5.0)
NEW - Ability to manually sort (order) folders in folder pane (most of the work by the Thunderbird team, adjustments by Betterbird) (fixed in 115.5.0) - Bug 1846550, Bug 1864510, Bug 1864582
NEW - Introduced pref betterbird.update.checkIntervalDays to configure time between update checks (in days) (fixed in 115.5.0)
FIXED - Turning multi-line view on/off wasn't immediately reflected in the thread pane/message list (fixed in 115.5.0)
FIXED - Performance issue when using search/virtual folders (fixed in 115.5.0) - Bug 1864247
FIXED - Checking for add-on updates hung at "Updating add-ons" under some circumstances (fixed in 115.5.0)
FIXED - Error Console output when checking updates for add-ons not hosted on ATN (fixed in 115.4.2) - Bug 1861372
FIXED - After restart, unread/total message counts not shown for collapsed servers in the folder tree (fixed in 115.4.2) - Bug 1835548
NEW - Shift+Click on "Mark Folder Read" will also mark all sub-folders as read (fixed in 115.4.0) - Bug 500762
CHANGED - On Windows Betterbird now uses its own registry entries to better co-exist with a Thunderbird installation (fixed in 115.4.0)
FIXED - Bad X-MOZ-LASTACK attributes from iCloud CalDAV calendars not tolerated (fixed in 115.4.0) - Bug 1849849
FIXED - Couldn't open or save encrypted message attachment (fixed in 115.4.0) - Bug 1689326, Bug 1837247
NEW - Pref mail.download.open_attachments_readonly to disable that attachments are opened read-only (fixed in 115.3.2)
FIXED - Fixed broken activation when clicking system tray icon on some Linux KDE installations (fixed in 115.3.2)
CHANGED - Improved activation when clicking system tray icon on Linux Mate (fixed in 115.3.2)
NEW - "Open Link in Browser" in compose window via context menu (fixed in 115.3.1) - Bug 695142
FIXED - SMTP: Limit messages per connection with new pref mail.smtpserver.default.max_messages_per_connection (fixed in 115.3.1) - Bug 1854567
RESTORED - Menu bar at the top of the main window (not underneath the new unified toolbar)
RESTORED - Total and unread/selected count removed from status bar (further improvements in 115.1.0, GitHub #183) - Bug 1831667
RESTORED - No more connecting lines in threaded view - Bug 1829470
RESTORED - Visual feedback during Quick Filter Search - Bug 1831500
RESTORED - Broken feed functionality, a lot of breakage in Thunderbird "Supernova": Feed updates, icons, etc.
MITIGATED - Problem with restoring message and folder tabs after restart on large profiles with many calendars - Bug 1841411
NEW - Vertically aligned tabs
NEW - Attachment list on top
NEW - Header pane resize
NEW - Minimize to system tray on Linux (KDE, Gnome and Xfce desktops), improved in 115.2.1
CHANGED - Improved portable launcher. Portable installation can now be moved without loss of functionality
CHANGED - New program icons for Mac (compliant with Apple rules)
CHANGED - Tab titles restore quicker (not a fix for tab restoral problem, see above)
CHANGED - More Troubleshooting Information now also displays identity and server keys
NEW - New preference gloda.list.immediate to show the search result as list immediately without having to click "Show results as list". Values: 0: Facet view, 1: Facet view and list view, 2: List view only. - Bug 580252
FIXED better - Display/repair of some messages (incl. subject) with incorrect charset headers - Bug 1739609
FIXED - Can't drag contact on mailing list in other address book - Bug 1782397
FIXED - Invalid Atom feeds with missing title not accepted, for example German Heise c't feed


After initial problems with the 115 series, version 115.3.0 and later should be safe to use. Some work is still in progress, see a list of various "Supernova" bugs not fixed in the 115 series yet. For important bugs Betterbird 115 already includes fixes.

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