The CPP/A document describes an Endpoint element for SMTP containing an
e-mail address (page 38?). According to the Messaging Specifications, any
ebXML over SMTP requires both "to" and "from" lines in the SMTP header. It
is not clear from the description that if the sending protocol is SMTP,
that there has to be a "from" e-mail address somewhere in the CPA. In
fact, if one direction is SMTP and the other is HTTP, I don't see that
there is a place for two e-mail addresses. Can someone clarify what
happens in this case?