2.2.3.13 PidTagAddressType
Data type: PtypString ([MS-OXCDATA] section 2.11.1)
The PidTagAddressType property ([MS-OXPROPS] section 2.576) contains an Address Book object's e-mail address type. It MUST have the value "EX" for all objects on an NSPI server.
The PidTagAddressType property is not present on objects in an offline address book (OAB).