The higher ups have recently asked about this as I'm sure there are compliance issues that need to be addressed. I was under the assumption that Exchange uses opportunistic TLS or StartTLS to try to encrypt all outbound emails and falls back to unencrypted transport.
Is this the case with newer versions of Exchange? How reliable is this and how often is StartTLS employed by other mail servers?
If this method for encrypting mail traffic cannot be used reliably what are some other alternatives on the server side of things?