Exchange seems to be working fine in general but we've noticed a few emails have gone astray lately. I can tell this because we use a border email server which scan for spam/virii and then passes the good stuff back to Exchange internally. In this case, the message ID was found to be a legit email and delivered to the recipient (border email server says) however the recipient did not receive this message and Exchange message tracker shows nothing between +1 -1 day from the sender. It does show other emails on that day and even this same sender on other days. I was quite shocked to not find any trace of it via the message tracker, is there any other way of seeing where it might have gone?