An addition symbol to add two destinations selected from a list of
destinations including a group name representing mail addresses of
multiple members, and a subtraction symbol to subtract a mail address of
an arbitrary member from a group destination are predefined in electronic
mail software, so that when an electronic mail message is transmitted to
multiple destinations from a communication terminal, the addition symbol
or the subtraction symbol is placed between one destination and the other
destination in a destination field in a window for composing an
electronic mail message to add a destination address to or delete a
personal address of a group member from a group name.