The client adds recipients (2) to an e-mail message by using the RopModifyRecipients ROP ([MS-OXCROPS] section, as specified in [MS-OXCMSG] section For each recipient (2), the client sets the PidTagRecipientType property (section to 0x00000001 for a primary recipient, 0x00000002 for a Cc recipient, or 0x00000003 for a Bcc recipient. For details about the RecipientRow structure, which is used in the RopModifyRecipients ROP request buffer, see [MS-OXCDATA] section