Re: Help - How to unwind an SRS address?

On Sat, 2004-11-20 at 12:12 +0100, Koen Martens wrote:
> Hi,
> 
> There is no regex to do so, since you need to verify the crypthographic
> cookie. Without the secret key, you won't be able too. Of course you can
> just rewrite it ignoring the cookie, but that isn't something I advice
> (depending on the application of course).

Since he says he doesn't want to install anything, I assume he isn't
trying to undo SRS that he's done himself, for forwarding bounces. I
assume he's just trying to obtain the original reverse-path which some
forward performing SRS has mangled.

My first response would be to contact the site which is performing SRS
and ask them not to mangle the addresses when forwarding mail to you.
It's only necessary to perform SRS when forwarding mail which has a
reverse-path for which SPF is published, _AND_ which is being forwarded
to a site which actually rejects mail for an SPF failure.

I actually implemented this kind of conditional rewriting logic in my
own SRS implementation (http://www.infradead.org/rpr.html) but I've not
actually had to add many domains to the 'spf-afflicted-domains' list so
I'm about to remove the SRS on forwarding.

In the long term, it looks like there are better answers to the
brokenness of SPF than SRS, so the futile attempt to get SRS deployed
ubiquitously might as well be abandoned.
 
-- 
dwmw2