On Fri, 2004-02-27 at 14:55 -0500, Meng Weng Wong wrote:
| Most modern mail forwarding systems rewrite envelope FROM:s, or have the
| ability to do so if enabled. Can you enable this for your system?
|
Ther's no point fighting these sorts of things; for forwarders, the tide
is turning, and we can sink or swim.
The mail you quote is somewhat disingenuous. It is blatantly untrue that
'most modern mail forwarding systems rewrite envelope FROM:s'.
Such rewriting is _not_ widespread; furthermore it cannot become so
until a safe scheme for doing so is invented.
Does anyone have figures for the number of hosts actually doing such
rewriting?
For that matter, does anyone have figures for the number of hosts
actually _using_ SPF to _reject_ mail rather than just tagging it, or
the number of domains publishing SPF records _without_ '?all' at the end
rendering them mostly irrelevant?
Without actually being used to reject mail, after all, it's just another
heuristic.
The avalanche has started. It is too late for the pebbles to vote.
I'm not voting. I'm making an observation.
There are, in general, two types of scheme for fixing the problems with
email.
Firstly, there is the type of scheme which throws the baby out with the
bathwater and completely reinvents SMTP from scratch, with none of the
original design flaws. These are, in general, a fine experiment in
academic theory without and real practical chance of replacing the
status quo.
Secondly, there is the more realistic incremental approach which can be
retrofitted without losing compatibility with systems which have worked
for decades. These tend to work end-to-end without the need for any
changes to be made by non-participating hosts.
It seems that SPF is a half-way house between the two. It _appears_ to
be superficially compatible, and fails to make a clean start with a
fundamentally saner design than the original all-trusting SMTP. Yet it
still requires changes at _every_ forwarding site on the Internet,
damaging its chances of widespread adoption for real.
In this way, it unfortunately appears to offer the worst of _both_
worlds.
--
dwmw2