Classify Email Addresses

Says what each address is to the practice: Internal (a team member's sign-in address or a
connected mailbox), Client (one of a client's email rules matches the address or its domain),
NotClient (the address or its domain is marked as not a client) or Unknown, in that order of
precedence. A client match names the client only when exactly one client matches and the caller
may see it. At most 100 addresses per call.

Requires: ViewAll on Mailbox.