Routing ACKS.

I'm trying to get an ACK routed to a different process in our Test environment and here is the router setup:

I have a rule in the target router to send to an operation.

The problem I'm running into is that the HL7 ACK coming back is marked as "Discarded", so it's not even getting to the second router.

This is the ACK message:

I've tried everything I can think of, but once the ACK hits the router, it gets marked as discarded and then things just stop.  This particular interface is sensitive and it would be good to generate an email if there is a problem with the enrollment (MSA-3)

Any ideas would be appreciated.

Thanks

Andrew