def send(self, content_type='HTML'):
        """ Takes the recipients, body, and attachments of the Message and sends.

        Args:
            content_type: Can either be 'HTML' or 'Text', defaults to HTML.

        """

        payload = self.api_representation(content_type)

        endpoint = 'https://outlook.office.com/api/v1.0/me/sendmail'
        self._make_api_call('post', endpoint=endpoint, data=json.dumps(payload))