Abstract: An attached file management system is provided which can reduce the data amount occupied by the attached file when transmitting and receiving electronic information. A server includes a communication part which intermediates the transmission and reception of electronic mail between PCs, a storage part which stores storage data, a file management part which determines whether or not an electronic mail transmitted by the PC includes a file. If the file is included, the file management part determines whether or not the file exists in the storage part. If the file does not exist, the file management part stores the file in the storage part and updates the storage data. The server also includes a server information generation part which generates access information based on the storage data if the electronic mail transmitted by the PC includes a file. The communication part transmits the access information to the transmission-destination PC.