I'm new to TLS Authentication but have read and followed the following document with fine detail: http://technet.microsoft.com/en-us/library/bb266978(EXCHG.80).aspx
I have configured this in a virtual test environment and all appears to be working... mail flows... I can inspect the verbose email logs and I can see the certificate being sent and received within the log.
I am just not 100% sure that this means that TLS is working!
Does anyone know specifically with 100% certainty what fields in the message headers and/or the verbose logging which indicate that TLS is enabled and operational?