To deal with a receiver which is not adaptable to a multi-media E-mail without omitting information transmission when the multi-media E-mail which comprises an image, a voice, an on-line questionnaire and a credit card input function, etc., is directly transmitted to a mail address with an unknown reception type.

A machine arranged at the side of a server confirms whether the receiver environment of a domain name in a mail distributing destination is recognized or not. When it is recognized, a mail type is generated for a character form mail receiver or for a web mail receiver having a specified reception environment and distributed to the address. The multi-media E-mail for automatically reading the receiver environment and changing the type is transmitted to the mail address which is not recognized in the judgement process.