Re: [exim] support for domainkeys

On 9/24/2004 11:37, "Jim Roberts" <punster@???> wrote:

> Question: Is the IP a bounce returns from *certain* to be the same IP that
> the mail was originally sent to? (I am willing to bet not). If not, then
> there's no point in tracking the destination IP.
>

No. The bounce will come from some machine which decided it didn't like the
message. That may very well be a different machine from the one the message
was delivered to. Even if the same machine bounces, the bounce message
might be delivered out of a different IP than the IP by which it arrived.

In our case, a bounce will never come from the IP to which the connection
was made which created the bounce. (We do have a few cases in which we
"have to" accept then bounce...it has to do with using the same Exim for
MTA-to-MTA work and for submission, combined with the remarkably bad job
many MUAs make of a multiline reject message, combined with an option we
offer to virtual domain customers to reject incoming mail to bad local parts
with a multi-line custom message.)

By this time next week, we should have submission separated from MTA-to-MTA,
and we'll be able to reject at SMTP time in those cases for MTAs, while
accepting and bouncing for submissions (which still can result in
undeliverable bounces if people mis-configure their MUA, but at least that's
unlikely to disturb some other user somewhere else).

--John