Lexmark MS823
Scan to RightFax (XML) eSF app is unable to connect to the RightFax server versions 16.6 and 20.2. This issue occurs when clicking the Apply or Test button on the application’s configuration page. The eSF app gets an error saying that the RightFax server address (IP address) is invalid and asks for a valid server address.
Você não consegue acessar o Embedded Web Server da impressora? Verifique o Endereço IP ou a conexão de rede para resolver o problema.