If the ServerPort property is 0, then the port to be used
          will be inferred from the ServerType and Secure
          properties.
          Conversely, if the ServerPort is set to one of the standard
          FTP ports (21 or 990) or standard HTTP ports (80 or 443), and
          ServerType is undefined, then the ServerType and
          Secure properties will be inferred from the
          ServerPort.
          The ServerPort property will be used by the Connect
          method if the ServerPort parameter for Connect is
          missing.