PidTagAddressType Property

The value of the PidTagAddressType property ([MS-OXOABK] section is a string that names the messaging system that the address is destined for. It is used to assign responsibility for an e-mail address to the right transport provider. The string value provided by the PidTagAddressType property contains only uppercase alphabetic characters from "A" through "Z", and the numbers from "0" through "9". The value of the PidTagAddressType property is also used to designate the correct format for the PidTagEmailAddress property ([MS-OXOABK] section

If a client tries to compose a message to a user whose address type is not in the server's list of known address types, the message will produce a non-delivery report unless the client itself, acting as the message transfer agent, is able to deliver the message by using an alternate transport that bypasses the server.

The following table lists the address types that are known at this time. The common address types include "EX", "SMTP", "X400", and "X500".

Messaging system

Value of the PidTagAddressType property

Microsoft Exchange




X.400 Message Handling System


X.500 Directory Services