The OwnerSearchKey property returns a MAPI search key for the meeting owner of an item.
Appointment and RecurringAppointment objects
String
Read/write
The OwnerSearchKey property is supplied by MAPI and identifies the person who owns the meeting. The meeting owner is usually the user who creates the meeting, except when a delegate creates the meeting instead. For example, Bob could create a meeting request and assign Randy as the meeting owner.
The format of the data in this property is not interpretable by most applications and should be treated like a handle.
CreatorSearchKey
OwnerEntryId
OwnerName