X.400 is a protocol of Email standardized by UIT. It forever known of really significant deployment. However it is always used today as a Réseau with added-value in the exchanges EDI. It was the subject of many polemics, in connection with its comparison with smtp, this last having clearly carried it.

Its addresses were form /C=FR/O=Bull/CN=Support.

The principal heritage of X.400 is the vocabulary, MTA ( Message Transport Agent ) or MOULTED ( Message To use Agent ), always used today.

In France, France Telecom markets her X.400 network under the name of Atlas 400 or more simply Atlas.

External bonds

Page of the UIT on X.400