Abstract: In a system for registering and managing the E-mail information that is necessarily used commonly by a plurality of users/groups professionally, a group of a plurality of user information including addressers and addressees who relate to the transmission/reception is extracted from the E-mail information to be registered, and the user information is stored in an access right group management information corresponding to the E-mail information as a user group who deserves the common access right. Thereby, the necessary access right is set to each E-mail information easily and correctly. When a user requests an access to the E-mail information, the access right group management information is referred to thereby determine whether there is the access right or not.