In an e-mail processing system with a predetermined limit on the number of destination addresses of a piece of e-mail to be sent, the present invention determines whether the number of destination addresses of a piece of e-mail being viewed to be returned to everyone exceeds the predetermined limit when directed to be returned to everyone for the e-mail being viewed, and generates a piece of return mail creation screen with predetermined addresses in the e-mail being viewed being set as destinations of the piece of return mail when the predetermined limit is determined to be exceeded and generates a piece of return mail creation screen with everyone's address for the piece of e-mail being viewed being set as a destination of the piece of return mail when the predetermined limit is determined not to be exceeded. This configuration improves viewability and operability, for example, when a user directs to create a "Return to Everyone" mail. This configuration can increase the number of users to be provided with the service.