URL Link has been wholly re-written to be a WebExtension. The version here will not work on Thunderbird as it requires a minor tweak for that which cannot be uploaded here. Please see the separate Thunderbird add-ons site instead: https://addons.thunderbird.net/en-GB/thunderbird/addon/url-link/ The force-submenu option does not yet do anything as menus cannot currently be recreated on-the-fly (Fir