X.400 <messaging> The set of {ITU-T} communications standards covering {electronic mail} services provided by data networks. X.400 was widely used in Europe and Canada. X.400 addresses tend to be much longer than {RFC 822} ones. They consist of a set of bindings for country (c), {administrative domain} (a), {primary management domain} (p), surname (s), given name (g). For example, the X.400 address, c=gb;a=attmail;p=Universal Export;s=Bond;g=James; might be equivalent to RFC 822 [email protected] [Reference?] (2003-06-24)