Thunderbird for Mac

New

• S/MIME popup shows signature, digest, encryption algorithms and key sizes.
• Default address book for manually added contacts configurable with mail.addr_book.add_item_default_uri.
• Enterprise policy DisableQRExport can disable QR export.
• OAuth add-ons can override built-in settings for selected domains and hostnames.
• Manual account config streamlined with Exchange, Graph, and custom OAuth support.
• Custom OAuth support for IMAP and SMTP servers.
• PKCE and external browser fields added to custom OAuth settings.
• Enterprise policy DisableExperimentalFeatures for disabling experimental features.

Fixed

• Unread count dock badge disappeared on macOS restart when no mail window opened.
• IMAP tags did not sync automatically across clients.
• Embedded SVG images appeared broken when Display Attachments Inline was disabled.
• Holding arrow keys failed to smoothly navigate the folder pane.
• Mark and Tag menu bar items were disabled in search results.
• Quick Filter ignored address book display names shown in message lists and headers.
• Attachment filters could disappear or return no results in global search.
• Body search failed for quoted-printable messages ending on a soft line break.
• Failed encrypted send did not preserve draft.
• Failed account setup left an incoming server that blocked account recreation.
• Removing an account did not remove its OAuth token from the password manager.
• Account Hub prompted for calendar credentials immediately after successful login.
• Filters could copy empty messages to Local Folders during startup mail download.
• Closing message filters wrongly warned completed newsgroup filters were running.
• Autoscroll icon was missing directional arrows in scrollable messages.
• Apple Mail text attachments may not appear in MIME messages.
• Forwarded messages could display incorrect encoding.
• Thunderbird could crash due to improper database memory handling.
• Thunderbird could crash on shutdown while waiting for OAuth2 password entry.
• Thunderbird could crash while loading mail folders.
• Custom OAuth could not be disabled.
• Legacy IMAP tag changes were not sent to the server and reverted after refresh.
• Deleting an Exchange account retained the outgoing server settings.
• CalDAV calendars with offline support could stop fully synchronizing events.
• Offline cached ICS calendar changes were silently lost after reconnecting.
• Thunderbird upgrade disabled composition toolbar.
• Thunderbird upgrade disabled Settings menu for versions before macOS 13.
• Windows jump list menu no longer functioned correctly.
• Visual and UX improvements.
• Security fixes.