2.2.1.2.9 PidTagOriginalEntryId Property

Data type: PtypBinary ([MS-OXCDATA] section 2.11.1)

The PidTagOriginalEntryId property ([MS-OXPROPS] section 2.830) contains the original EntryID of the message, which is used to associate the full message item being downloaded from the server with the message header previously stored on the client.