administration management domain (X.400) (ADMD)
To enable the management of a worldwide MHS system, such a system is broken down into smaller units. For this purpose, X.400 has defined Management Domains( MD).
Private organizations are responsible for Private Management Domains( PRMD), while the national telecommunications companies are responsible for public Management Domains, the Administration Management Domains (ADMD). However, it can also be other providers. In Germany , these include Deutsche Telekom, IBM and General Electric.
Each country has at least one Administrative Management Domain. It is responsible for registering and addressingsubscribers. An ADMD consists of a mail transfer agent( MTA) and mailboxes and also handles cost accounting with the subscribers.