On Dec 7, 2005, at 1:35 PM, Edward B. Dreger wrote:
DO> Not all email is rejected within the SMTP session. You are
changing
DO> requirements for recipients that scan incoming messages for
malware. Fault
DO> them for returning content or not including a null bounce-
address. No one
DO> can guarantee an email-address within the bounce-address is valid,
Perhaps DSNs should be sent to the original recipient, not the
purported
sender. RFC-compliant? No. Ridiculous? Less so than pestering a
random third party. Let the intended recipient communicate OOB or
manually if needed.
Being refused by the intended recipient would be the cause for the DSN.
DO> furthermore a DSN could be desired even for cases where an
authorization
When auth fails, one knows *right then* c/o an SMTP reject. No bounce
is necessary.
This assumes all messages are rejected within the SMTP session.
DO> scheme fails. Why create corner cases?
The corner case is that a virus _might_ actually have a realistic
"From"
address. :-)
You mean bounce-address? A From address often has nothing to do with
where a message originated.
DO> DomainKeys and Sender-ID can not validate the bounce-address or
the DSN.
DO> Even with an SPF failure, a DSN should still be sent, as SPF
fails in
If you receive mail with
From: <[EMAIL PROTECTED]>
coming from 10.10.10.10, and everquick.net SPF records indicate
that IP
address is bogus, how can you possibly justify "that mail may indeed
have come from how it's apparently addressed"? Doubly so when a virus
is known to spoof "from" addresses!
SPF has _nothing_ to do with the From address.
Once again, not _all_ messages are rejected within the SMTP session.
False positives are not 0%. To ensure the integrity of email
delivery, not including message content and using a null bounce-
address should be the recommended practice at the initial recipient.
If you do not want to see DSNs with spoofed bounce-addresses, employ
BATV at _your_ end should be the recommended practice. You would not
need to insist that anything special be done at millions of other
locations.
-Doug
