This invention allows setting which of user defining sheet name and print sheet name is to be used for each print sheet type when receiving a print sheet error notification from a network printer and notifying a client of a recovery request message. In order to implement a function not supported by a color copying apparatus, a control apparatus is interposed between a client terminal-connected network and the color copying apparatus. The control unit in the control apparatus receives a recovery request message from the color copying apparatus. In this case, the control unit refers to a user defining sheet database to determine which user defining sheet name and print sheet name is to be used as a sheet name contained in the recovery request message to be sent to a print job-issuing client terminal. The control unit transmits the determined recovery request message to the client terminal.