PURPOSE: To prevent transmission from being missed by simplifying destination designation at the time of transmission by respectively converting destinations designated by official positions to addresses in the electronic mail system provided with a an office managing function.

CONSTITUTION: A destination input part 1 designates the destination for each document to be mailed. Assuming that the two items of address designation and one official position designation destination are set, as to the two items of address designation, inputted number and address are registered as transmitting mail information through a destination write part 4 to a mail managing data base 3. On the other hand, as to one official position designation destination, designated mail number and the office information of the data are retrieved from the office managing data base 6 by using an office retrieval part 7 first. Next, the name belonging to the relevant office is extracted from the retrieved office information and the designated official position code by an official position judge part 8, and this is acquired as the address by an address acquisition part 9. Namely, the address is acquired from the designated official position.