The open source email client Thunderbird just released version 144.0, and while it is not a feature packed update, it is one that fans of the classic desktop mail app should not skip. The new build improves stability, enhances compatibility, and patches a long list of bugs affecting everything from OpenPGP encryption to calendar management.
One of the most important changes is the Flatpak runtime update, which now uses Freedesktop SDK 24.08. This is good news for Linux users since it keeps the Thunderbird Flatpak current with newer libraries and sandboxing improvements. That helps maintain security and reliability across distributions.
Beyond that, this release focuses on fixing real world issues. Copying text from some error alerts finally works again, and Fastmail CalDAV users should now be able to authenticate without problems after a forced OAuth regression was corrected. The update also fixes attachment deletion problems, missing folders under “Recent,” and incorrect display of sender avatars.
Users who rely on OpenPGP or S/MIME will appreciate that Thunderbird 144.0 resolves several encryption and certificate bugs. These include missing headers, failed certificate testing, and unreadable PQC signed mail. Calendar users get improvements too, such as reliable drag and drop event copying, better reminders, and smoother handling of certificate errors during calendar discovery.
Other refinements include improved multi attachment handling, clearer profile import behavior, small user interface updates, and multiple security fixes. The development team continues to show strong dedication to keeping Thunderbird private, cross platform, and user controlled in a world full of cloud locked mail apps.
Thunderbird 144.0 is available now for Windows 10 and later, macOS 10.15 or newer, and Linux with GTK+ 3.14 or higher.
