Peter Gutmann wrote:
"Umberto Ferrara" <ferrara(_at_)exentrica(_dot_)it> writes:
Suppose that a PEC users sends a message to a non-existent ordinary recipient
and that PEC provider system receives a SMTP 5xx error type. If it doesn't
propagate this error, the sender won't be able to know that his message could
not be delivered.
The solution could be forwarding the error message into an anomaly envelope
containing a short description of the problem
If it never gets to the end user that the sender has a (trust) relationship
with, how is key management for the anomaly envelope handled?
Peter.
The "trust" relationship is not between users, but between (PEC)
servers. So in this example, there is no "trust" relationship, since the
receiver would be a normal user from the "outside" world wrt to the PEC
system. This normal user will receive a PEC Transport Envelope signed by
the sending PEC provider.
If, on the contrary, a message is sent from a source outside of the PEC
system to a PEC user, the receiving PEC provider inserts that message
inside an Anomaly Envelope and signs it.
--Alba