184.108.40.206.2.1 Determining the Email Address
If the client is publishing the data for the logged-on user, the client finds the Address Book object of the logged on user by matching its EntryID with the value of the PidTagMailboxOwnerEntryId property ([MS-OXCSTOR] section 220.127.116.11) of the message store.
If the client is publishing the data for another user, the client gets the Address Book object by performing an ANR with the full name or partial name of the delegator. For details about how to resolve a name, see [MS-OXOABK] section 18.104.22.168.
The client gets the email address from the PidTagEmailAddress property ([MS-OXOABK] section 22.214.171.124) of the Address Book object.