this article demonstrates a quick code in VB.Net to reference an outlook mail item from the hard disk.
to run the code, first you need to open your MS Outlook, select a message in your inbox, then save it in your hard disk in the c:\ drive, and name it "Test", so the full path of the message item file is "c:\test.msg"
the following code will allow you to reference the message item using Outlook Object Library:
Dim oApp As New outlook.Application
Dim oItem As outlook.MailItem
oItem = oApp.CreateItemFromTemplate("C:\test.msg")
MessageBox.Show(oItem .Body.ToString)
Note: do not forget to import "Microsoft.Office.Interop" Library