I have to search AD objects based on mail addresses (from/to/cc). Currently I try to search for all AD objects, with a mail property that matches an address :
As result I have to expect an unique account to store its GUID. But it seems that mail isn't unique enough.
Under which circumstances is it possible, that 2 AD-Objects (different GUID) can have an identical mail attribute? And what's a best practice to map an MS-Exchange mailbox address to an AD-Object?