What Is X 400
What Does X.400 Mean? X.400 is a suite of protocols defining standards for email messaging systems. It was defined by the ITU-TS (International Telecommunications Union—Telecommunications Sector) in 1984 and again in 1988. Used as an alternative to the more common email protocol called Simple Mail Transfer Protocol (SMTP), X.400 is more widely used in Europe and Canada than in the U.S.. Techopedia Explains X.400 X.400 is more complex than SMTP. However, it is familiar to many email server administrators who use Microsoft’s Exchange email server....