Abstract: In an arrangement of a mail terminal 1, an electronic mail system 2, a job control terminal 4, and a computer system 3, a user makes a proposal of a file operation via a mail by way of the mail terminal 1. The electronic mail system 2 stores therein the proposal mail, exchanges this proposal mail with the job control terminal 4, and furthermore distributes a file operation result to the respective mail terminals. The job control terminal 4 receives a mail from the electronic mail system 2, and interprets the proposal mail, thereby executing a conversion from a mail ID into a host ID, a judgement of an access authorization with respect to the designated file, and a production of an instruction to the computer process system 3. Furthermore, an execution host computer is selected by monitoring operation conditions of the host computers.