IRonMaN - The returns were put inside the post office while the post office was still open and before the truck came for the day and theoretically should have left town that day.  The post office in our small town has told us, though, that it no longer time stamps any mail at our location.  Rather, it is sent to a processing center 120 miles away for processing.  So it is hard to tell what the post mark might have been.  Unfortunately, we did not know this fact until after we inquired.