Recently I had a reason to look into the available MAPI properties of a message object. Microsoft pointed me to MFCMAPI, a tool available for free at codeplex.com. The tool allows you to walk through your email profile, drilling down through all sorts of intersting objects. The screenshot below shows my Inbox, and the specific properties of a message. Notice cool flags like PR_REPLY_REQUESTED. Unfortunately the property I was hoping to find was a timestamp for when the message was first opened and it doesn’t exist yet. I did learn however that Exchange 2007 SP2 adds a message auditing feature that allows you to audit such actions as message opened. Read more about Exchange auditing here.
Download MFCMAPI here.