A facsimile server machine that is easy to access from a client personal computer but does not allow the client personal computer to rewrite machine settings without authentication. The facsimile server machine includes a controller for executing a plurality of HTTP tasks. Each HTTP task has a port number. The controller decides which HTTP task should be executed based on instructing information from a client personal computer and a port number appended to that HTTP task. The relationship between the HTTP task port numbers and the client personal computers is defined in a table created in the machine. The controller refers to the table when executing the HTTP task, using the specified information.