As many of you know, Thunderbird development has been moving slowly away from Firefox development since around 2015. However, many changes from Firefox still land in Thunderbird due to the shared nature of the core codebase.

One of these changes is the move to WebExtensions, which has been particularly tough for Thunderbird thanks to the rich nature of the older APIs (which allowed developers such as Opacus to access properties on the emails such as the body, addresses and attachments).

Thunderbird development resources are working hard to provide updated APIs for WebExtensions, but in the interim they have provided scaffolding to allow the older style extensions to work with a little modification.

To that end Opacus have updated the two current Thunderbird extensions to support Thunderbird 63.0 and up. Both versions are now available on the Thunderbird Addons site:

Professional
Standard

Note that Thunderbird 63.0 and up are currently in beta, so to use the new versions you'll need to be running the beta release of Thunderbird.

- The Opacus Team