Why do we need to implement a custom message builder and formatter?

To handle a content type that is not supported by the ESB profile.

To process an incoming message structure that is not supported by existing constructs in the ESB, convert it

into the ESB profile's canonical message format, and convert the outgoing message from the canonical format to the expected message structure.

To support a transport protocol not available out-of-the-box in the ESB profile.

To handle a messaging structure in the ESB profile.