If you hit File>Send from inside Rhino, it opens a mail window in your default mail program, but as soon as you put the cursor in the To: box, you get a “Server Busy” error message that you can’t get out of… Only way out is to kill Rhino AND the mail program and lose any unsaved work.
I never use this myself, but a client just called and asked me about it… so I tried myself and of course promptly lost the last 10 minutes of my unsaved work… (so beware trying !!!)
–Mitch