docs: def send(self):
          """
          Attempts the delivery through recipient's domain MX records.
          """
          try:
              for mx in self.mxrecords:
                  logging.info('Connecting to {} {}...'.format(mx, self.port))
                  server = smtplib.SMTP(mx, self.port)
                  server.set_debuglevel(logging.root.level < logging.WARN)
                  server.sendmail(
                      self.sender, [self.recipient], self.message.as_string())
                  server.quit()
                  return True
          except Exception as e:
              logging.error(e)
              if (isinstance(e, IOError)
                      and e.errno in (errno.ENETUNREACH, errno.ECONNREFUSED)):
                  logging.error(
                      'Please check that port {} is open'.format(self.port))
              if logging.root.level < logging.WARN:
                  raise e
          return False