To surely receive the contents of an electronic mail even when an opposite party cannot receive the mail due to a network trouble, etc., by transmitting the contents of a transmitting mail also to a FAX of the opposite party.

This device includes an electronic mail preparing section 1 where a document that is transmitted in an electronic mail is prepared by a user, a transmission setting input section 2 where the transmitting destination (address) of the electronic mail is inputted by the user, a format conversion section 3 where the text data which are transmitted in an electronic mail is converted into a FAX format, an electronic mail transmitting section 4 where an electronic mail is transmitted to the inputted mail address and a FAX transmitting section 5 where the text data in an inputted electronic mail is converted into the image data receivable by a FAX via the section 3 and the image data are transmitted to a FAX number that is set by the user.