To allow inspecting whether a security check of a planned outgoing email is finished in an outgoing email check system, a check data providing apparatus 2 of an outgoing email check system 100 stores check information distributed from a check information management apparatus 1, appends check data generated based on the check information to a header of a checked planned outgoing email, and transmits the email to an email transmitting apparatus 9. A check data inspecting apparatus 3 stores the check information distributed from the check information management apparatus 1, inspects the check data extracted from the planned outgoing email received from the email transmitting apparatus 9 based on the check information, determines that the transmission is permitted when the check data of the planned outgoing email matches the check information, and determines that the transmission is rejected when the check data does not match the check information. The email transmitting apparatus 9 executes a transmission process only for the planned outgoing email for which the transmission is permitted.