1.3 Overview
The Outlook Item (.msg) File Format is a syntax for storing a Message object, such as an e-mail, an appointment, a contact, a task, and so on, in a file. Any properties that are present on the Message object are also present in the .msg file.
For information about a Message object and its properties, see the Message and Attachment Object Protocol, which is described in [MS-OXCMSG].