Comment 5 for bug 248612

You can call "gnome-open" with a mailto: URL. So, a script which converted the sample email text file into a URI (encoding etc.) and passed it to gnome-open would be an option. E.g.:

mailto:<email address hidden>?subject=Monthly%20report%20for...&body=urlencoded%20body%20text

Of course, I doubt gnome-open does any conversion between the mailto URI and whatever is accepted by your input client, so this would be a leaky abstraction.