Returned message content in DSNs is often essential information for debugging of mail system problems. Blindly insisting that DSNs should not return subject message content is shortsighted. We have already crippled the mail system too much as the result of naive and shortsighted spam countermeasures. Keith > > Yes, DSNs that include content are a problem. Dropping NDN or DSN > that indicate a failure of some sort also makes email less reliable. > Email has become far less reliable as a result. The TPA-SSP scheme > for DKIM allows a return path to authorize the DKIM signature only to > encourage the issue of DSNs. Again, those DSNs should still exclude > original message content. > >>> A safer approach would be to format all DSNs per RFC3464 and remove >>> original message content. >> >> I'd hope that a majority of receivers already does this, that's state >> of the art for some years now. Or rather "truncate" is state of the >> art, not complete removal of the body. > > It would be rather tempting to make this mode of DSN operation a > requirement. At any point of time, we see some 20 million different > MTAs which do not remove message content are currently being > exploited. Perhaps we should add a new list that indicates which > MTAs do not remove content on DSNs? We could then let our customers > decide whether they want traffic from these MTAs as well. Not all > that different from open-proxies and aimed at restoring DSN integrity. _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf