The description of msg format expansion
The msg file is a message, being created or stored in Microsoft Outlook mail client. This file contains different parameters of electronic message, including date, the sender data, info about receiver, subject and message content itself. This format is compatible with other programs, which use Messaging Applications Programming Interface (MAPI) from Microsoft.
You may create the MSG file, if you apply simple drag-and-drop mechanics on a message, task item, contact or appointment from Outlook folder to a folder in Explorer. In such a way, the message subject will be applied instead of the name of the MSG file in Windows Explorer. You may use the same procedure backwards from Explorer to Outlook, and you will obtain the same view the message had before the exporting routine.