Set Kopano Deskapp To Be Default Mailto App

This is the command to set the Kopano Deskapp app to be the default app for mailto: links in an Linux xdg-compatible desktop environment. It assumes that a kopano-deskapp_mailto.desktop file exists :
xdg-mime default /usr/share/applications/kopano-deskapp_mailto.desktop 'x-scheme-handler/mailto'
If the kopano-deskapp_mailto.desktop doesn't exist (in /usr/share/applications or ~/.local/share/applications) then create one in either of those two places with the minimum of this:
[Desktop Entry]
Name=Kopano DeskApp mailto
GenericName=Mailto URI handler
Comment=Create Mails from mailto uri in Kopano DeskApp
Exec=kopano-deskapp --durl=%u
Icon=kopano-deskapp Terminal=false Type=Application StartupNotify=true MimeType=x-scheme-handler/mailto NoDisplay=true
Use the following to query what it is currently set to:
xdg-mime query default 'x-scheme-handler/mailto'