-----Original Message-----
From: owner-spf-discuss(_at_)v2(_dot_)listbox(_dot_)com
[mailto:owner-spf-discuss(_at_)v2(_dot_)listbox(_dot_)com] On Behalf Of
Julian Mehnle
Sent: vrijdag 8 juli 2005 14:53
To: spf-discuss(_at_)v2(_dot_)listbox(_dot_)com
Subject: Re: [spf-discuss] Explain please
Julian Mehnle wrote:
Forwarding without sender rewriting is a bad thing because it cannot
be distinguished from regular envelope sender forgery. If forgers can
evade responsibility by just claiming to be forwarders, then the forgery
problem cannot be solved.
Exactly.
When the SMTP protocol was devised, there were no provisions preventing
anyone from using anyone's SMTP server. An oversight, for sure. It got
fixed, by means of closing open relays. Similarly, with the advent of the
SMTP protocol, nothing stopped anyone from using anyone's envelope-from
address. Also an oversight (measured by today's standards).
And so, since forwarding without sender rewriting cannot be distinguished
from regular envelope sender forgery, tie-ing the envelope-from identity
to the relay, which is what SPF does, is a good thing; it fixes the
particular hole.
- Mark
System Administrator Asarian-host.org
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"If you were supposed to understand it,
we wouldn't call it code." - FedEx