PURPOSE: To rapidly transmit mails with contents partially different from each other in accordance with destinations by simple operation by providing the titled system with a means for specifying a specific part in a mail and automatically inserting data of a corresponding part in other data into the specified part and a means for automatically transmitting/accumulating a mail to/in a destination determined by the inserted part.

CONSTITUTION: A part in a mail to be required to change its contents in accordance with a destination is specified by the 1st means. Then data corresponding to the specified part are inserted by the 2nd means. Since the another data based upon the 2nd means and the specified part in the mail are correspondingly stored, the data can be inserted into the specified part. One or more data to be inserted and its destination to transmit the inserted mail are stored in another data as a pair. The inserted mail is transmitted to the destination stored as a pair of data by the 3rd means.