code: async def help(self, command_name=None):
          
          if command_name is None:
              command_name = ""
  
          code, message = await self.do_cmd("HELP", command_name)
  
          return message
docs: Sends a SMTP 'HELP' command.
  
          For further details please check out `RFC 5321 § 4.1.1.8`_.
  
          Args:
              command_name (str or None, optional): Name of a command for which
                  you want help. For example, if you want to get help about the
                  '*RSET*' command, you'd call ``help('RSET')``.
  
          Raises:
              ConnectionResetError: If the connection with the server is
                  unexpectedely lost.
              SMTPCommandFailedError: If the HELP command fails.
  
          Returns:
              Help text as given by the server.
  
          .. _`RFC 5321 § 4.1.1.8`: https://tools.ietf.org/html/rfc5321#section-4.1.1.8