-----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 David
Woodhouse
Sent: Tuesday, December 07, 2004 4:56 AM
To: spf-discuss(_at_)v2(_dot_)listbox(_dot_)com
Subject: RE: [spf-discuss] Re: RFC 2821 and responsibility for
forwarding
On Mon, 2004-12-06 at 12:57 -0500, terry(_at_)ashtonwoodshomes(_dot_)com
wrote:
The problem is, how do you distinguish an email that was
*actually* forwarded from one that is
*pretended* to be forwarded (by fake headers generated by
the spammers MTA).
You can't. But this is already the case with SPF and SRS. I
can generate
a mail with a reverse-path something like:
SRS0=xx=yy=ashtonwoodshomes(_dot_)com=terry(_at_)srs(_dot_)infradead(_dot_)org
The recipient's ISP can't distinguish that fake from a genuine mail
which was really forwarded, in the general case. All they can
do is look
up 'srs.infradead.org' in the reputation database.
Forget about SRS, there are some serious problems with it: even Meng has
admitted to such.
Please refute the argument with more recent and seemingly better SES solution.
Anyone can argue
that an old solution is bad, but truly one needs to argue against the most
recent version of the
solution.
Umm, I think this is watering down SPF too much,
Well yes, but it's _already_ that watered down. It's _already_ no more
useful than CSV, when you actually stop for a moment to consider the
situation holistically.
I have considered it holistically, your simply wrong. CSV only does HELO
checking. SPF does
Mail-From checking, with optional HELO checking.
If SPF only did HELO checking, it would be no better then CSV. But it also
does Mail-From, and for
domains where that is possible it is definitely better (SES implemented and/or
SRS on forwarders
where forwarding allowed)
Anyway, SPF is easier to deploy then CSV, and is more deployed then CSV. That
*alone* if one just
considered using the HELO checking of SPF makes SPF more userful then CSV.
Now please stop bashing products (SPF or CSV or whatever) and try be
constructive with your
criticism (or at least show all the facts): Your responses keep looking like
sales pitches that one
has to read between the lines to see what is really going on.
Terry Fielder
Manager Software Development and Deployment
Great Gulf Homes / Ashton Woods Homes
terry(_at_)greatgulfhomes(_dot_)com
Fax: (416) 441-9085
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