I was messing around in Settings and somehow made Thunderbird my default email application instead of Geary. I did something so that I can no longer use the toggle switch to choose Geary; Thunderbird is now the only option. Is there a Terminal command that will reset Geary as the default email program?
xdg-mime query default 'x-scheme-handler/mailto'
xdg-settings set default-url-scheme-handler mailto firefox.desktop
xdg-mime default firefox.desktop 'x-scheme-handler/mailto'
That sets Firefox as the default email program, not Geary.
… that was an example.
You’ll have to substitute the desktop file for Geary there.
Regular Applications desktop files will be in
Flatpak Applications desktop files will be in