1.6 Applicability Statement
This protocol is designed to return the name of an name service provider interface (NSPI) server before the client engages in any NSPI requests. It is also designed to return the FQDN (1) of a mailbox server, as described in [RFC1035], when a client only knows the DN (1) of a mailbox server with which it can make a network connection. In practice, this is necessary in several cases:
When creating client mail settings, a client uses an NSPI server to read an Address Book object representing its mailbox, which includes the DN (1) of the messaging server that hosts the mailbox.
When connecting to the wrong mailbox or public folder server, an error will be returned containing the DN (1) of the correct server.
When connecting to another user's mailbox, having only the PidTagAddressBookHomeMessageDatabase property ([MS-OXOABK] section 22.214.171.124) for that mailbox.