Mozilla has just unveiled Thunderbird version 144 of its widely adopted free and open-source desktop email client, now available for download.
Among the notable changes, copying text from some error alerts now works properly, and an issue with Fastmail CalDAV access caused by an OAuth regression has been resolved.
The release also fixes a bug where the Delete key didn’t prevent users from deleting attachments in OpenPGP messages—a small but critical fix for users handling encrypted mail.
The email organization also gets a few corrections. For instance, newly created folders now correctly appear under the “Recent” section when moving messages, and sender avatars now display properly when using the “Name via address” format.
Thread sorting has also been improved, so conversations show up as expected, instead of only threads with unread top messages floating to the top.
Regarding security, Thunderbird 144 restores proper handling of OpenPGP v6 and PQC keys, ensures all headers are signed when creating digitally signed messages, and resolves several issues with S/MIME certificate testing—particularly for old or invalid certificates and sub-identities.
On the calendar side, users will notice fewer hiccups when working with events and tasks. Thunderbird now correctly handles reminders for tasks without end dates, allows event copying by drag-and-drop in month or multiweek views, and fixes repeated certificate error prompts during calendar discovery.
A few user experience details were addressed, too. The “Reply All” button now shows up again when using Microsoft Exchange accounts, and Thunderbird should no longer hang while checking multiple accounts for new messages. Crashes that could occur in various scenarios have also been ironed out.
Linux users will likely appreciate the updated Flatpak runtime, which bumps Thunderbird to the latest Freedesktop SDK 24.08 base, ensuring better compatibility with modern desktop environments and dependencies.
For more information, see the announcement. Thunderbird 144 is available as a direct download from thunderbird.net.
