code: async def quit(self):
          
          code = -1
          message = None
  
          try:
              code, message = await self.do_cmd("QUIT")
          except ConnectionError:
              # We voluntarily ignore this kind of exceptions since... the
              # connection seems already closed.
              pass
          except SMTPCommandFailedError:
              pass
  
          await self.close()
  
          return code, message
docs: Sends a SMTP 'QUIT' command. - Ends the session.
  
          For further details, please check out `RFC 5321 § 4.1.1.10`_.
  
          Returns:
              (int, str): A (code, message) 2-tuple containing the server
                  response. If the connection is already closed when calling this
                  method, returns (-1, None).
  
          .. _`RFC 5321 § 4.1.1.10`: https://tools.ietf.org/html/rfc5321#section-4.1.1.10