18.104.22.168.3 Contact Photo Attachment
The contact photo attachment is a picture attached to the Contact object. The Attachment object MUST have the PidTagAttachmentContactPhoto property (section 22.214.171.124.2) set to nonzero (TRUE). For more details about Attachment objects, see [MS-OXCMSG] section 2.2.2. Additionally, the following properties MUST be set on the Attachment object, as specified in [MS-OXCMSG]:
The value of the PidTagAttachDataBinary property ([MS-OXCMSG] section 126.96.36.199), which is the contents of the attachment, SHOULD be in JPEG format. Support for other formats is as determined by the implementer.
The PidTagAttachExtension property ([MS-OXPROPS] section 2.583) SHOULD be set to ".jpg".