def _construct_message(self):
        """Build the message params."""
        self.message["text"] = ""
        if self.from_:
            self.message["text"] += "From: " + self.from_ + "\n"
        if self.subject:
            self.message["text"] += "Subject: " + self.subject + "\n"

        self.message["text"] += self.body
        self._add_attachments()
Build the message params.