X.400 Connector

You can use the X.400 Connector to establish an X.400 messaging route between two Microsoft Exchange Server sites or between a Microsoft Exchange Server site and a foreign X.400 system. An X.400 messaging route defines the path that an X.400 message follows to reach its destination. It enables the MTAs in both sites or systems to communicate. A foreign X.400 system is a messaging system other than Microsoft Exchange Server that complies with the 1984 or 1988 X.400 standards.