X.400 Communication equals on of the available eBiss communication channels which allows communication via X.400 (Telebox).
X.400 stands represents Message Handling System (MHS), defined by the Open Systems Interconnection (OSI) initiative for the cross-vendor communication of systems, devices and components.
X.400 therefore defines the exchange of electronic messages based on the OSI reference model.
In Germany, X.400 is often still known under the old brand name Telebox400 of the German Federal Post. Meanwhile the successor Deutsche Telekom designates it as BusinessMail X.400. EDI systems often use X.400 to transfer the data.