Re: SPF and bouncing

On Sat, 7 Apr 2012, Alessandro Vesely wrote:
> I'd say no, because of the better-cause-deserving diligence that some
> organizations put in making sure that the envelope sender is kept
> unaltered on forwarding to external mailboxes.  That policy is
> supported by "alias expansion" as standardized by SMTP.

We aren't discussing forwarders, but ordinary SMTP with only one hop
across the border.

Although the conspiracy is quite relevant to forwarders.  It destroys
them and is even harsher on SRS forwarders than legacy forwarders.

The only sustainable hope for a forwarder is a side deal with the admins
of the ultimate recipient server to obtain the same super-whitelisting
(overriding even mailbox diskspace quota and immune to automated
blacklisting) that backup MXes have.  Then it really doesn't matter what
the MAIL FROM: is.

I hear some forwarders are actually considering the hack of beginning the
outgoing transaction simultaneously with the incoming one, so that it
doesn't respond to the sender->forwarder CR LF '.' CR LF until it has the
response from the forwarder->recipient transaction.  That would be
conspiracy-compliant but explicitly not RFC-compliant (RFC 1047, RFC 1123
section 5.3.3).

---- Michael Deutschmann <[email protected]>