Scott,
Thanks for the reply. We have not gone any farther with this. We are in the process of upgrading to 4.3 to take advantage of the better throughput and Global Monitor connection. We still need to determine if there might be a way to accomplish this in the future.
To your point about the audit trail, we are hoping that the inbound log which denotes what messages are passed and which are blocked will give us the audit of all messages received and their disposition.
I will let you know if we figure anything out.