PGP-based security enhanced mail gateway (SEMAIL) with POP authentication for large scale organizations

In this paper, we propose a security tool for security enhanced mail gateway (SEMAIL). SEMAIL is a mail server package designed to provide PGP (pretty good privacy)-based e-mail security to all the members of an organization. SEMAIL is attempting to solve the problems incurred by implementing PGP in large scale organizations. In this paper we introduce a POP before SMTP implementation that authenticates users before sending messages using SMTP. POP before SMTP for SEMAIL is designed to perform user level authentication in such way that the number of "receive before send" requests for the purpose of authentication is drastically reduced. Moreover, it overcomes problems induced by the ordinary implementation in a DHCP environment. As a result, SEMAIL with POP before SMTP is expected to become more secure and practical for large scale organizations.