code: def _parse_outgoing_mail(sender, to, msgstring):
      
      global OUTBOX
      OUTBOX.append(email.message_from_string(msgstring))
      return
docs: Parse an outgoing mail and put it into the OUTBOX.
  
  
      Arguments:
      - `sender`: str
      - `to`: str
      - `msgstring`: str
  
      Return: None
      Exceptions: None