OpenNavo

Mozilla Thunderbird Beta

Thunderbird · A macOS beta build of Thunderbird, an email client with calendar and contacts capabilities, intended for testing before the stable release.

CaskCommunicationAuto-updatesApple silicon · Intel
Homepage
From homebrew/cask
30-day installs6#1944 in App
1-year installs173Last 365 days
Latest version159.0b2yesterday · Oct 14
Download size162MBarm64 / x86_64 · dmg
Release cadenceWeekly10 releases in 30 days

  1. 159.0b2

    LatestOct 14 · Wed

    OpenNavo editorialAdded to Homebrew Oct 14 17:15

    The official standalone entry for 159.0b2 says this release has no Thunderbird changes requiring release notes.

    Highlights

    • The official 159.0beta page explicitly identifies beta 2, released October 14, 2026. Its “Fixed in beta 2” group states that there are no Thunderbird changes requiring release notes in this release.
    • Features, fixes, and security-related issues above that group are earlier series entries, not newly attributed changes in 159.0b2. This statement does not establish the absence of build or dependency changes or known issues.

    Official sources

  2. 159.0b1

    Oct 12 · Mon

    OpenNavo editorialAdded to Homebrew Oct 12 23:16

    159.0b1 adds Linux tray unread indicators and Graph calendar discovery. Fixes cover mail, attachments, search, authentication, CardDAV/CalDAV, Graph throttling and calendars, including Reply-To deception, SMTP/RSS injection and remote-content risks. The official page explicitly applies to beta 1; full source is retained below.

    Localized summary

    159.0b1 adds Linux tray unread indicators and Graph calendar discovery. Fixes cover mail, attachments, search, authentication, CardDAV/CalDAV, Graph throttling and calendars, including Reply-To deception, SMTP/RSS injection and remote-content risks. The official page explicitly applies to beta 1; full source is retained below.

    Complete official English source

    Thunderbird Desktop Version 159.0beta | Released October 12, 2026 Check out the notes below for this version of Thunderbird. As always, you’re encouraged to tell us what you think, ask for help, or file a bug in Bugzilla. These notes apply to Thunderbird version 159 beta 1 released October 12, 2026. System Requirements: Details What’s New new Linux tray icons indicate unread mail and show its count in the tooltip 1946946 new Graph calendars are auto-detected on new account creation 2052324 What’s Fixed fixed Non-ASCII IMAP tags could exceed server length limits and be rejected 2073409 fixed Zoom Text Only option did not work in the View menu 2075594 fixed Multiple messages were printed even after canceling the print dialog 2076335 fixed Save All and Detach All failed for attachments with invalid filename paths 2076435 fixed First Wrap Long Lines toggle did nothing in View Source 2076654 fixed POP3 NTLM authentication failed because the password was sent incorrectly 2076742 fixed Search Messages menu option was enabled but did not work for saved search folders 1923075 fixed Quick Find shortcut (/) only worked after Ctrl+F was used once 2067593 fixed Unicode email addresses could hide different Reply-To destinations 2076034 fixed Newsgroups with UTF-8 names could display duplicate or incorrect messages 2068200 fixed View > Folders did nothing in Calendar and Tasks tabs 2078239 fixed Global search results did not display recipients in the To field 2075316 fixed Forwarding malformed MIME messages could omit attachments 548507 fixed Retry and Save Locally failed after a sent-folder copy error 2068501 fixed Closing an unmodified compose window prompted to save when using Body Text 2075909 fixed MP4 attachments could be truncated when forwarding messages 2077839 fixed Inline images disappeared when editing local or POP messages as new 2078784 fixed EWS/Graph accounts could fail when outgoing server settings were incomplete 2067724 fixed Account Hub Edit Configuration did nothing for Exchange and Graph accounts 2075408 fixed First message filter condition could not be removed even when others existed 2070351 fixed CardDAV address book sync stopped when the server rejected an invalid sync token 1912673 fixed CardDAV passwords were not saved, causing repeated login prompts after restart 2030007 fixed Malformed message database files could cause excessive CPU usage 2077833 fixed IMAP namespace root folders were inaccessible due to duplicated folder names 2005701 fixed Excessive Microsoft Graph requests caused throttling and delayed message display 2075389 fixed SMTP addresses with line breaks could inject unintended commands 2075922 fixed POP3 sessions remained active after canceling the password prompt 2076749 fixed Remote content could load in news articles with missing message headers 2079222 fixed RSS feeds could inject arbitrary Message-ID and References headers 2077741 fixed Large ICS calendar files could exhaust memory and freeze Thunderbird 2058953 fixed CalDAV calendars could stop syncing after a network error until restart 2076473 fixed Yearly recurring events with multiple times per day only appeared at the first time 2074745 fixed Visual and UX improvements 2075076 2078240 2079609 2079622 See All Releases

    Sources

  3. 158.0b5

    Oct 7 · Wed

    OpenNavo editorialAdded to Homebrew Oct 7 22:55

    Improves Quick Filter and fixes search, OpenPGP, contacts and calendars.

    Changes
    Improves Quick Filter responsiveness and matching names without accents.Fixes crashes during message-body searches.Fixes OpenPGP key unlocking, handle leaks and protection-state issues.Fixes forgotten CalDAV/CardDAV credentials after restarting.Fixes CardDAV setup prompts and syncing newly added contacts.Fixes Ctrl+Enter accidentally confirming send prompts and sending duplicates.
    Changes 2
    Fixes RSS filtering losing tags and blocking later feed items.Fixes localized calendar editing errors and saving updated credentials.