The present invention enables accurate detection of risks from an electronic mail message. In a mail inspection unit, an information extraction section extracts text and a mail address from electronic mail accumulated in a journal DB, and a text normalization section normalizes the text. A sort-information saving section generates text sort information according to the score obtained from a sorting engine, and stores it in a mail-management-information storage section. A personal-information saving section extracts personal information from a personal-information storage section according to the mail address, and stores it in the mail-management-information storage section. Finally, a risk-level determination section compares the information stored in the mail-management-information storage section with the information stored in a category-information storage section to determine the risk level of the electronic mail.