On Thu, 30 Jun 2005, Bruce Lilly wrote:
Not necessarily; for better or worse, a number of sites use multiple
MTA relays within their own administrative domain, and aliasing
expansion might well occur at a separate upstream host from the one
effecting actual delivery. There is nothing particulary
non-compliant about such a configuration, though it does have the
characteristic of forcing a bounce where a single-host arrangement
might be able to return an SMTO 5xx reply code
There's nothing to prevent the front-end MX hosts in such a setup from
having access to the list of valid users, so it doesn't "force"
accept-and-bounce instead of reject.
Tony.
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f.a.n.finch <dot(_at_)dotat(_dot_)at> http://dotat.at/
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GOOD.