Mozilla has released Thunderbird version 147 of its widely adopted free and open-source desktop email client, now available for download.
One of the most visible additions is a new “Show Full Path” option for the folder pane when using compact view modes. This makes it easier to navigate complex mail setups by displaying the full folder hierarchy instead of truncated names.
Alongside this, Thunderbird 147.0 introduces a new preference, mail.useLocalizedFolderNames, allowing users to control whether special folder names are localized. In addition, special folders are now localized using a restricted and more predictable set of names.
On the bug fixes side, multiple issues affecting folder handling have been resolved, including failures when compacting several folders at once, incorrect names in unified archive subfolders, and display problems with deep folder hierarchies or long folder names.
Search behavior has also seen notable improvements. Problems where searches failed to complete due to unparsable local folders have been addressed, and search widgets now correctly display selected status and priority. Plus, the Settings menu search has also been corrected so that queries for attachments properly surface the relevant options.
Regarding stability fixes, several crash scenarios have been eliminated, including crashes during Exchange account setup, when marking all messages as read, and when emptying the EWS trash. Startup performance has improved, too, for users with many folders who do not rely on subscriptions, reducing launch delays.
On the Exchange Web Services and SMTP handling side, Thunderbird now correctly prompts for passwords when required during EWS message sending, handles HTTP 500 backoff errors more gracefully, and avoids hangs when multiple messages are queued for SMTP delivery. Additionally, account creation via OAuth2 for EWS now properly reports errors when setup fails.
Finally, other fixes address OpenPGP-signed message handling, blocked RSS feed updates due to broken icons, calendar alerts for connection issues, and the inability to create tasks with start or due dates. Users of the Japanese locale will also benefit from a fix that restores the ability to create message filters.
For more information, see the announcement. Thunderbird 147 is available as a direct download from thunderbird.net.
