Thunderbird 146: OpenPGP Configuration and AES Migration

Mozilla's Thunderbird developers have released version 146.0 of the open-source email client. The update's central new feature is the option to configure the preferred OpenPGP keyserver directly through the user interface. OpenPGP integration is one of the most important security features for users who rely on end-to-end encryption for their email communication. This eliminates the need to manually edit configuration files in the future, significantly simplifying the use of key servers for importing and managing public keys. Furthermore, Thunderbird automatically migrates existing logins to more modern AES encryption.

However, the majority of the update addresses bugs: the developers have fixed several causes of crashes, including issues when renaming or moving mail folders and in server subscription logic. A memory leak that occurred when opening new windows from the context menu of the folder pane has also been resolved.

For macOS users, the update brings an important correction: copying email attachments via drag-and-drop to the desktop or into folders now works as expected again. This function was broken in previous versions. Additionally, Thunderbird now correctly marks Microsoft Office attachments with the MOTW (Mark of the Web) label when opening them, which contributes to security under Windows.

Improvements to EWS and User Interface

The integration of Exchange Web Services (EWS) – introduced in Thunderbird 145 – has received several refinements. Offline flags for EWS folders are now saved correctly and persist after a restart. The option "Select this folder for offline use" in the folder properties also now functions as intended. Crashes could previously occur during manual setup of EWS accounts via the Account Hub – this source of error has also been fixed.

In the area of the user interface, the developers have corrected several inconsistencies. For instance, the delete button in the toolbar could erroneously remove attachments instead of messages. The "Recent destinations" submenu when moving messages is now correctly sorted by modification time. Problems with the display of account names in the account column and with tag assignment in the context menu are also a thing of the past.

Further corrections concern the import of vCards, where the file selection only displayed VCF files, and the Account Hub setup, which now provides more accurate success messages about the configuration source. Extending the validity period of OpenPGP keys previously set an incorrect date – this bug has also been fixed.

According to the release notes, the update also addresses several security vulnerabilities without specifying them in detail – however, Mozilla's security page lists no security fixes for the new version. Thunderbird 146.0 is available for download for Windows (version 10 and later), macOS (10.15 and later), and Linux (GTK+ 3.14 or higher). Details about the new version can be found in the release notes. The developers are also working in parallel on Thunderbird Pro, a paid service with email hosting, encrypted file sharing, and scheduling, which is currently in internal testing.

(fo)