Microsoft Exchange directories let you create special objects called External Recipients. Think of these objects as address book entries that represent recipients in external messaging systems. You can modify the Schema Mapping policy so that you can map a remote object to a User object or any other desired Identity Vault object. For example:
<class-name> <nds-name>User</nds-name> <app-name>remote</app-name> </class-name>
If you decide to make this change, you should also add the Internet EMail Address attribute as a required attribute to the Create policy as shown in the following example:
<create-rules> <create-rule class-name="User"> <required-attr attr-name="Given Name"/> </create-rule> </create-rules>
An Internet EMail Address attribute is required to create an External Recipient object in the Exchange directory. Failure to add the Internet EMail Address attribute results in an error when you try to create an External Recipient.