"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.