A secure message contains information that can only be shared between a trusted CSR and an authenticated customer. A secure message has the confidential flag set.
A Secure Message must be sent over a trusted channel, and a message becomes a secure message when it is received on a trusted channel. Some points to remember are:
Forwarding and carbon copying options on secure messages are disabled.
A response to a secure message also becomes secure.
A secure response message can normally be sent only to the sender of the original message on the same channel as the original message was sent.
Learn more about Secure Messaging.