On Mon, 14 Apr 2008 19:06:05 +0100, Douglas Otis
RFC 2822 does not depend upon SMTP as being the message exchange
protocol. In addition, future message exchange protocols may depend
upon different address resolution protocols, such as PRNP. PPNP
avoids any reliance upon DNS, for example. Any protocol that might
replace DNS may also adopt a strategy of DNS independence. Unless
ADSP specifies policies are limited to SMTP, it would be incorrect to
conclude existence checks can or should depend upon DNS resource
But how do you know which protocol the message was written for?
If it arrives at your site via SMTP, then you should apply the ADSP rules
appropriate to SMTP. If it actually started life being transported by
XXTP, then you just have to assume that the XXTP to SMTP gateway had fixed
it up (e.g by not letting it through at all if it was going to violate
Conversely, if it arrives at your site via XXTP, then it may or may not be
worth trying ADSP on it (depending on whether or not you have DNS access).
It is again really a matter for any earlier SMTP to XXTP to have sorted
the matter out (e.g. by verifying it and not passing it on if it failed).
Just think in terms of "XXTP" == "Carrier pigeon" :-) .
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131
Email: chl(_at_)clerew(_dot_)man(_dot_)ac(_dot_)uk Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K.
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