You can go in to a specific text stream and change times/dates but then it becomes just a text in essence. If this is what they are providing, then it is meaningless.
You can reset your computer clock and it will do all the resetting of any new emails with the old date, but when ‘sent’ anywhere that are overhead handshakes between the servers that process the transmission are not changed.
It would be difficult to make it completely chronologically pure as that would require resetting all the servers that touch it along the way. If they are asked to show this ‘trail’ my guess is that they will stonewall this harder than this hard drive crash crap, because if they are caught screwing with the entire system that way, that smacks of just plain old treason.
Resetting the server clock would cause all kinds of problems including accessing the domain servers which I assume the Exchange server wasn’t - that is not a recommended configuration. That it turn would mean logins to the Exchange server would fail.
A significant time differential on a LAN causes connection failures. That very problem has come up here with FReepers asking for assistance as to why computers could not connect with each other, the solution simply being to check/update the date/times.
I believe the workstation clock would not come into play at all with MS Exchange.
If the email (notifying of the hard drive “failure”) recipients were internal, which I assume they were, then the situation is vastly simpler because there would be no other mail server involved.
I wouldn’t know how to do it off the top of my head, but there are a number of low-level tools for working with MS Exchange and do believe that the timestamps could be edited and doubt that regardless of whether or not it would work, there would be any other way to accomplish back-dating, including resetting computer clocks.