bz wrote:
Aredridel <aredridel(_at_)nbtsc(_dot_)org> said:
Directing bounces is the most difficult part of such an exchange, since
SMTP specifies that the MAIL FROM is also the place where bounces should
go to, leaving no application protocol level source of identity data.
The only solution is to have the originating system relay bounces to the
appropriate destination as a separate transaction, instead of
short-circuiting and going straight to the unverifiable sender address.
a recent discussion on ietf-smtp has been addressing the question:
"Do the must 'bounce' rules need to be relaxed for virus infected messages?"
Would a relaxation of the 'must bounce' rule also help here?
For the time being, the IETF should publish a BCP RFC recommending against
bounce messages in response to viruses known to forge MAIL FROM. Other than
that, I think the 'must bounce' specification is a good one, and provides
great benefit in a world in which bounce is guaranteed to be directed to
someone in a position to react to it.
Specifically, if the domain in MAIL FROM cannot be forged, and a site
receives an email-carried virus with a given domain in the MAIL FROM, I
would imagine that most administrators would like to receive notice of the
crap leaving their network.
Philip Miller