Microsoft

*EntryId: If there is an e-mail address part, after the de-encapsulation step, perform a lookup against the address book for an entry any of whose proxy addresses matches this address. If an entry is found, construct an address book entry ID from that entry’s DN as specified in [MS-OXCDATA]. If no entry is found, construct a one-off entry ID from the display name, address type, and e-mail ... ................
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