On all of the users I have tested, email tracking doesn't seem to display the correct tracking information until it is opened.
To put it another way:
I send an email and select the option to notify me when it is read. I receive 10 or more notifications. I let these notifications sit in my inbox for a day or two. After which, they are moved to another folder.
When I go into my sent items and look at the item, I am unable to see the tracking information. If I go and open one of the read receipts, go back to my sent items, I then can open tracking. However, I only see that the person in which I opened the read receipt notification from has "read it".
I am using Outlook 2010 and Exchange 2010. Any thoughts?