Betterbird: Release Notes

Betterbird 128 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 section below for features added before the 128 series, and check the release notes of the 102 series for features added before the 115 series.

Based on Thunderbird 128.5.2esr, release notes.

Fixed in this version:

CHANGED - Incompatible add-ons are now blocked, including "CardBook" and "Tag Toolbar", details here
CHANGED - Remote content now allowed in encrypted messages after unblocking on a RED banner. Use at you own risk as decrypted content of the message may be leaked to an attacker (EFAIL attack).
FIXED - Linux: Minimise to tray not working on Wayland (since Wayland has no concept of minimising)
FIXED - Images sometimes distorted, problem introduced in 128.4.3 and 128.5.0 with "improved" image resizing
FIXED - Wrong icon on "Debug Add-ons" tab
FIXED - Problem with Linux Movemail

Features and fixes exclusive to Betterbird (new in the 128 series):

NEW - End-of-year appeal 2024 (128.5.0)
NEW - New pref mailnews.virtual_folders.verbose for logging virtual folder cache operations to the console (128.5.0)
CHANGED - Improved logging to the Error Console when mbox corruption is detected (128.5.0)
FIXED - Content of virtual folder not correct after update to base folders. Issue in caching of search results in the old Mork backend. (128.5.0)
FIXED - Virtual folder based on body search not working when message received via POP moved by filter. This also led to erroneous mbox corruption logging. (128.5.0)
FIXED - Fixed image dimensions ignored, problem introduced in 128.4.3 with improved image resizing (128.5.0)
FIXED - Messages moved from POP Inbox via filter remain in Inbox and reappear after Repair. Compact not always removes them. (128.5.0) - Bug 1890253
FIXED - Complex expressions not evaluated correctly in some rare cases (when double group ending was followed by additional terms) (128.5.0) - GitHub #365
FIXED - Quick filter by "subject only" not updating result correctly (128.5.0)
FIXED - Various issues with account colours: Account manager widget not correctly initialised, full row colour not working in cards view, compose window identity pulldown menu with incorrect background colour. These problems were caused by errors in the integration with Thunderbird's poor implementation. (128.5.0)
FIXED - Search folders based on multiple folders from one account needlessly showed the colour of this account. Now colours are only shown if more than one account is involved in the folder. (128.5.0)
FIXED - "Overflowing" images, also in links, could not always be resized satisfactorily (128.4.3)
CHANGED - Errors encountered while parsing an mbox file are logged to the Error Console (128.4.2)
FIXED - Enhancement of cache for virtual/search folders, console message then cache can't be used (128.4.2) - Bug 1923520
FIXED - Windows: Installer not correctly signed with Betterbird's certificate (128.4.0)
MAYBE FIXED - The Thunderbird team hopes that IMAP folder corruption is fixed with this release, see comment above (128.3.3)
FIXED - Ability to manually sort (reorder) folders in folder pane not working in 128.3.2esr-bb13 (128.3.3)
FIXED - Issue related to the performance improvements for virtual folders (128.3.3)
FIXED - Linux: Corrected DBus application name to betterbird, changed WM_CLASS/StartupWMClass to eu.betterbird.Betterbird (128.3.2)
FIXED - Attachments of PGP encrypted messages couldn't be opened, regression introduced in 128.3.0 through a faulty Thunderbird fix (128.3.2) - Bug 1924637 Bug 1924856
FIXED - Crash when deleting/moving/copying messages stored in mbox format while option "Allow antivirus clients to quarantine individual incoming messages" was in use (128.3.1 build 2)
FIXED - Poor performance of virtual/search folders due to suboptimal use of cached results (128.3.1 build 2) - Bug 1923520
FIXED - Windows: Installer (installer.exe) not correctly signed with Betterbird's certificate (128.3.1 build 2)
NEW - Preference mailnews.database.global.indexer.max_body_part_size to allow Gloda (Global Database Index) to index larger messages (128.3.1)
NEW (experimental) - Pref mail.notification.show_on_app_screen to show native Betterbird new mail alerts on application screen instead of primary screen (128.3.1) - Bug 637830
FIXED - Performance issue with search folders (128.3.1)
FIXED - Windows: Executables and DLLs not correctly signed with Betterbird's certificate (128.3.1)
FIXED - Windows: Betterbird icon for notifications not correctly displayed in Windows Settings: Notifications & actions ("Manage Notifications") (128.3.1)
FIXED - Mbox envelop dates not maintained when message moved/copied to another mailbox (128.3.1)
FIXED - Feed account breakage introduced in 128.2.2esr-bb10 (128.3.0) - Bug 1920339
FIXED - Inappropriate yellow "new mail" star shown when saving IMAP draft or template (128.3.0)
CHANGED - New mail indicator will show on thread parent when collapsed thread receives a new message (128.3.0) - Bug 242300
FIXED - Account colour wasn't applied for "Unread Folders" and "Favorite Folders" in compact mode (128.3.0)
FIXED - Using "View > Threads > Unread" and "View > Threads > Threads with Unread" didn't always work (128.3.0) - Bug 1921618
FIXED - "Apply columns to" sometimes failing after processing a certain number of folders (128.2.2) - Bug 1872595
FIXED - Mac: ⌘1 to restore the main window didn't work (128.2.2) - Bug 1857953
FIXED - Search with empty search values, for example |Subject is <empty>| or |To is <empty>|. (128.2.1)
FIXED - The so-called "cite prefix" On 21 Aug 2024 12:35, Betterbird looover wrote: was spell checked. Other spell check inconsistencies between inline and "normal" spell check. (128.2.0) - Bug 216235 Bug 635843
FIXED - Incorrect results with regex search "doesn't match" under some circumstances (128.2.0)
FIXED - Quick filter search with Address Book Match not working for LDAP address books (128.2.0)

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Fixes in early preview releases before 128.2.0:
NEW - New preference mail.startup.focus to set focus after startup: 0: no focus, 1: focus spaces toolbar, 2: focus folder pane, 3: focus message list - Bug 425025 Bug 1620310
NEW - Reversed threading when view is sorted by date descending, needs to be enabled with pref mailnews.reversed_threading - Bug 305741
NEW - Quick Filter Search can now also match Display Name and Nickname from the address books - Bug 460737
NEW - Preference mail.server.serverNN.disabled to disable accessing inactive servers now exposed in user interface
NEW - Unified folders can be added as favourite folders and are restored at startup or mode change - Bug 537342
CHANGED - mail.addressDisplayAuthor and mail.addressDisplayRecipients replaced by Thunderbird's mail.addressDisplayFormat: 0 = both, 1 = e-mail, 2 = name, also available in the UI
CHANGED - Improved feedback during Quick Folder Search
CHANGED - Improved performance when restoring view with secondary sort
CHANGED - Reduced thread indentation from 16px to 10px, fixed indentation of correspondents column in multi-line view
FIXED - Problem when moving a folder to a different parent when manually reordering subfolders
FIXED - New and renamed folders don't show under "Recent Folders" - Bug 1367034
FIXED - Wrong summary string in Window List panel widget on Linux Mate
FIXED - Result of folder compact overwritten by "Loading message..." - Bug 1901846
FIXED - Status bar counts not updating for Gloda views
FIXED - Adding a folder which is not an inbox/sent/drafts/archive/trash folder to a unified folder made it disappear from the folder list if the folder was not a child of the inbox/sent/drafts/archive/trash folder. This led to update errors on the unified folder. - Bug 1913806

Various minor fixes that Thunderbird isn't shipping yet:

Bug 188598 Bug 1468925 Bug 1836511 Bug 1836511 Bug 1875325 Bug 1911477 Bug 1912658 Bug 1912675 Bug 1912727 Bug 1917278 Bug 1918145 Bug 1919144 Bug 1924047 Bug 1928803 Bug 1931661 Bug 1934417 Bug 1935073 Bug 1935401 Bug 1935883

After initial problems with the 128 series, version 128.5.0 and later should be safe to use. See our home page for details.

Based on Thunderbird 115.16.3 and the Mozilla platfrom code of version 115.18.0 (incl. latest securiry fixes).

Fixed in this version:

NEW - End-of-year appeal 2024
NEW - New pref mailnews.virtual_folders.verbose for logging virtual folder cache operations to the console
FIXED - Content of virtual folder not correct after update to base folders. Issue in caching of search results in the old Mork backend. If the issue persists, repair the base folder(s) being searched.
FIXED - Complex expressions not evaluated correctly in some rare cases (when double group ending was followed by additional terms) - GitHub #365
FIXED - Search folders based on multiple folders from one account needlessly showed the colour of this account. Now colours are only shown if more than one account is involved in the folder.
FIXED - "Overflowing" images, also in links, could not always be resized satisfactorily. Fixed image dimensions maintained.
FIXED - Quick filter by "subject only" not updating result correctly
FIXED - Enhancement of cache for virtual/search folders, console message when cache can't be used; now also allowing base folders with no hits - Bug 1923520

Fixed in Betterbird, not fixed in Thunderbird 115.16.3 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 in the 115 series:

Bug 148624 Bug 522768 Bug 531319 Bug 956446 Bug 1368011 Bug 1520435 Bug 1678057 Bug 1691301 Bug 1799368 Bug 1811214 Bug 1812726 Bug 1823024 Bug 1837152 Bug 1843221 Bug 1851975 Bug 1852191 Bug 1854138 Bug 1859271 Bug 1861200 Bug 1862519 Bug 1862521 Bug 1862978 Bug 1865598 Bug 1868094 Bug 1868718 Bug 1870873 Bug 1873282 Bug 1873313 Bug 1873607 Bug 1875577 Bug 1876431 Bug 1876662 Bug 1877774 Bug 1877962 Bug 1878047 Bug 1880043 Bug 1884661 Bug 1891937 Bug 1893793 Bug 1896960 Bug 1897781 Bug 1898488 Bug 1905912 Bug 1908761 Bug 1909617 Bug 1910168 Bug 1910477 Bug 1912733 Bug 1917485 Bug 1923585

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

FIXED - Poor performance of virtual/search folders due to suboptimal use of cached results (fixed in 115.17.0) - Bug 1923520
FIXED - Total Message Count for not always displayed for Favorite Folders in the folder pane (when enabled) (fixed in 115.17.0) - Bug 1924356 Bug 1926279
FIXED - Windows: Installer not correctly signed with Betterbird's certificate (fixed in 115.17.0)
NEW (experimental) - Pref mail.notification.show_on_app_screen to show native Betterbird new mail alerts on application screen instead of primary screen (fixed in 115.16.1) - Bug 637830
FIXED - Performance issue with search folders (fixed in 115.16.1)
FIXED - Windows: Executables and DLLs not correctly signed with Betterbird's certificate (fixed in 115.16.1)
FIXED - Windows: Betterbird icon for notifications not correctly displayed in Windows Settings: Notifications & actions ("Manage Notifications") (fixed in 115.16.1)
NEW - Preference mailnews.database.global.indexer.max_body_part_size to allow Gloda (Global Database Index) to index larger messages (fixed in 115.16.0)
CHANGED - New mail indicator will show on thread parent when collapsed thread receives a new message (fixed in 115.16.0) - Bug 242300
FIXED - Search with empty search values, for example |Subject is <empty>| or |To is <empty>|. (fixed in 115.16.0)
FIXED - "Apply columns to" sometimes failing after processing a certain number of folders (fixed in 115.16.0) - Bug 1872595
FIXED - Mac: - ⌘1 to restore the main window didn't work (fixed in 115.16.0) - Bug 1857953
FIXED - Inappropriate yellow "new mail" star shown when saving IMAP draft or template (fixed in 115.16.0)
FIXED - Account colour wasn't applied for "Unread Folders" and "Favorite Folders" in compact mode (fixed in 115.16.0)
FIXED - Using "View > Threads > Unread" and "View > Threads > Threads with Unread" didn't always work (fixed in 115.16.0) - Bug 1921618
NEW - Reversed threading when view is sorted by date descending, needs to be enabled with pref mailnews.reversed_threading (fixed in 115.15.0) - Bug 305741
NEW - Unified folders can be added as favourite folders and are restored at startup or mode change (fixed in 115.15.0) - Bug 537342
FIXED - Linux: Double-displayed windows control buttons when global menu was used together with window title bar (fixed in 115.15.0)
FIXED - Adding a folder which is not an inbox/sent/drafts/archive/trash folder to a unified folder made it disappear from the folder list if the folder was not a child of the inbox/sent/drafts/archive/trash folder. This led to update errors on the unified folder. (fixed in 115.15.0) - Bug 1913806
FIXED - The so-called "cite prefix" On 21 Aug 2024 12:35, Betterbird looover wrote: was spell checked. Other spell check inconsistencies between inline and "normal" spell check. (fixed in 115.15.0) - Bug 216235 Bug 635843
FIXED - Incorrect results with regex search "doesn't match" under some circumstances (fixed in 115.15.0)
NEW - New preference mail.startup.focus to set focus after startup: 0: no focus, 1: focus spaces toolbar, 2: focus folder pane, 3: focus message list (fixed in 115.14.0) - Bug 425025 Bug 1620310
CHANGED - Reduced thread indentation from 16px to 10px, fixed indentation of correspondents column in multi-line view (fixed in 115.14.0)
FIXED - New and renamed folders don't show under "Recent Folders" (fixed in 115.14.0) - Bug 1367034
FIXED - Issue with Quick Filter Bar text entry. Characters were lost. Defect introduced in 115.13.0-bb30. (fixed in 115.14.0)
FIXED - Wrong summary string in Window List panel widget on Linux Mate (fixed in 115.14.0)
FIXED - Message opened from .eml file couldn't be saved" (fixed in 115.14.0 )- Bug 927640 Bug 1402550
FIXED - Problem when moving a folder while Favourite Folders are displayed (fixed in 115.14.0)
FIXED - Status bar counts not updating for Gloda views (fixed in 115.14.0)
CHANGED - Improved feedback during Quick Folder Search (fixed in 115.13.0)
CHANGED - Improved performance when restoring view with secondary sort (fixed in 115.13.0)
FIXED - Problem when moving a folder to a different parent when manually reordering subfolders (fixed in 115.13.0)
NEW (experimental) - Preference mail.server.serverNN.disabled to disable accessing inactive servers. When set, "Check for new messages at startup", "Check for new messages every MM minutes" and "Allow immediate server notifications when new messages arrive" must also be turned off manually. (fixed in 115.12.0)
NEW - Editing of message headers: Menu item also available in the context menu of the message list (fixed in 115.12.0)
FIXED - Formatting issues when replying to certain plaintext e-mails - Bug 1891203 (fixed in 115.12.0)
NEW - Diacritics ignored in search (search, quick search, filters) (fixed in 115.11.0) - Bug 506064 Bug 1839085
NEW - Linux: "Global Menubar" (Unity Menubar) now supported, set pref widget.gtk.global-menu.enabled (fixed in 115.11.0).
Known issue: The menus of the OpenPGP Key Manager window and the Calendar windows to create or edit events aren't made global.
CHANGED - When folder had manually reordered subfolders, new subfolders are added semi-alphabetically after special folders. (fixed in 115.11.0)
FIXED - Off-by-one pixel alignment of subject line in multi-line view (fixed in 115.11.0)
FIXED - Improvements to feed subscribe dialog, OPML file third party import, feed drag/drop in folderpane and subscribe dialog (fixed in 115.11.0)
CHANGED - Switched Windows system notifications to new Mozilla platform code to improve registering in the Windows Action Centre on Windows 11 (fixed in 115.10.0)
FIXED - A combination of text filter, negated tag filter and more than one tag button selected/negated sometimes gave wrong results (fixed in 115.10.0)
FIXED - Encoding problem when editing message headers under certain circumstances (fixed in 115.10.0)
CHANGED - "Quick Filter untagged messages" replaced with "Quick Filter button negation" (incl. untagged messages) (fixed in 115.9.0) - Bug 683809 Bug 744365
FIXED - Usage of add-on "Grammar Checker & Paraphraser – LanguageTool" prevented downgrade of message to plain text (fixed in 115.9.0)
FIXED - Linux-only: Better detection of Gnome desktop to avoid crash related to system tray notifications (fixed in 115.9.0)
FIXED - Subject sometimes not spell-checked (fixed in 115.9.0) - 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. (fixed in 115.9.0) - 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 in 115.9.0)
FIXED - Setting prefs mail.addressDisplayAuthor and mail.addressDisplayRecipients had no effect on a new profile (fixed in 115.9.0)
FIXED - Re-established secondary sort by date in "Grouped by Sort" views (fixed in 115.9.0) - Bug 1873353 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

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