Message Encryption Vs In-Transit Encryption

[dsdr0]

Message Encryption is for mail-based traffic only, as opposed to non-mail encrypted traffic, though it could be "stretched" to encompass all encrypted traffic with further descriptions. Could a generic "in-transit encryption" be created to encompass both symmetric/asymmetric point-to-point encryption. Then, whether it was an AD authentication request, PKI traffic, TLS, internal application traffic, and all secured communication (not file/disk encryption which would be different).