To provide a printer and a network system, which can set an environment that an electronic mail transmitter-side desires and which do not need to prepare a large quantity of various data on a font or the like on a self-device side.

First to N-th user nodes 121-12N and the printer 13 are connected on a network 11. The printer 13 receives an electronic mail from the user node 12 requesting printing and extracts/executes a script incorporated in the mail. Thus, printing data and a printing resource are obtained from the electronic mail itself or the other place on the network 11 so as to execute printing. When a fault occurs in the printer 13 and maintenance is required, a system manager incorporates the script showing the place of the program for maintenance into the electronic mail and sends it. Thus, remote maintenance can also be realized.