docs: def get_relay_ip_list(server=_DEFAULT_SERVER):
      '''
      Get the RelayIpList list for the SMTP virtual server.
  
      :param str server: The SMTP server name.
  
      :return: A list of the relay IPs.
      :rtype: list
  
      .. note::
  
          A return value of None corresponds to the restrictive 'Only the list below' GUI parameter
          with an empty access list, and setting an empty list/tuple corresponds to the more
          permissive 'All except the list below' GUI parameter.
  
      CLI Example:
  
      .. code-block:: bash
  
          salt '*' win_smtp_server.get_relay_ip_list
      '''
      ret = list()
      setting = 'RelayIpList'
  
      lines = _get_wmi_setting('IIsSmtpServerSetting', setting, server)
  
      if not lines:
          _LOG.debug('%s is empty: %s', setting, lines)
          if lines is None:
              lines = [None]
          return list(lines)
  
      # WMI returns the addresses as a tuple of individual octets, so we
      # need to group them and reassemble them into IP addresses.
      i = 0
      while i < len(lines):
          octets = [six.text_type(x) for x in lines[i: i + 4]]
          address = '.'.join(octets)
          ret.append(address)
          i += 4
      return ret