A remote server identifies based on unique identification information, model information, operator name information and/or owner name information, and a plurality of pieces of contact information. The remote server identifies trouble content information, estimated cause information, and seriousness information based on trouble content identification information. The remote server simultaneously transmits transmission information to contact addresses indicated by the plurality of pieces of contact information identified, the transmission information including the model information, the operator name information and/or the owner name information, date and time information, position information, the trouble content information, the estimated cause information, and the seriousness information. When troubleshooting intention information, indicating an intention to perform trouble shooting for the trouble, is received from any one of contact addresses indicated by the plurality of pieces of contact information, the remote server transmits the troubleshooting intention information to the other contact addresses.