Abstract: There is provided a message exchange service which can accept a message whose destination is a user who has not yet registered for the service and transmit, to the destination user, the message in a data format appropriate to the service in an ex post facto manner. A server device accepts profile information from a user wishing to use the service to proceed with registration of the user to the service, receives and records a message whose destination is an unregistered user who has not yet registered for the service together with identification information to identify the destination user, and transmits the message to a new registered user if it is determined, based on the profile information accepted from the new registered user and the identification information, that the new registered user who has registered for the service after the receipt of the message corresponds to the destination user.

Abstract: There is provided a message exchange service which can accept a message whose destination is a user who has not yet registered for the service and transmit, to the destination user, the message in a data format appropriate to the service in an ex post facto manner. A server device accepts profile information from a user wishing to use the service to proceed with registration of the user to the service, receives and records a message whose destination is an unregistered user who has not yet registered for the service together with identification information to identify the destination user, and transmits the message to a new registered user if it is determined, based on the profile information accepted from the new registered user and the identification information, that the new registered user who has registered for the service after the receipt of the message corresponds to the destination user.