On Tue, 7 Dec 2004, David Woodhouse wrote:
On Mon, 2004-12-06 at 13:11 -0500, Alan DeKok wrote:
You're assuming that messages go from source to destination in one
hop. While this is nice, the current design allows a message to
traverse multiple independent hops, all the while using the same "MAIL
FROM". This has a serious impact on the "blowback" problem, and any
possible solution.
I'm not assuming that. I'm saying that SPF doesn't make the problem any
worse than _other_ schemes will, if they cause the ultimate recipient to
reject mail which the {backup MX, relay, forwarder} does not reject.
Err, no. SPF does make the blowback problem much worse. Other schemes
create a few percent blowback. SPF enables 100% blowback. Thats much
worse.
Yes, but sharing live information about all of your users with a
backup MX is difficult to do in practice.
That may be your experience; it's not mine.
That's a general experience with any large mail system. Its also a problem
where different vendors provide backup mail services. Its only not a
problem on simple, small single server systems.
--
Av8 Internet Prepared to pay a premium for better service?
www.av8.net faster, more reliable, better service
617 344 9000