2.2.1.5 PidTagLastModifierName Property
Type: PtypString ([MS-OXCDATA] section 2.11.1)
The PidTagLastModifierName property ([MS-OXPROPS] section 2.767) contains the name of the last mail user to modify the object. This property does not apply to Folder objects and Logon objects. This property is read-only for clients.