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Re: [Asrg] Wierd reverse DNS resolution might affect spam filters

2006-06-23 11:44:11
David Wilson <David(_dot_)Wilson(_at_)isode(_dot_)com> wrote:

Some years ago a colleague told me that some resolvers, when doing rDNS
lookup with then perform a forward lookup of the hostname, to check that
the A records for the name contain the IP address with which you
started.

I believe this is usually done in the applications rather than in the
resolver itself.

If not true, perhaps it is something which SMTP servers should do
themselves, before using the rDNS name for authorization.

What do you mean "perhaps"? Decent MTAs (e.g. Exim) have been doing this
for many years.

Tony.
-- 
f.a.n.finch  <dot(_at_)dotat(_dot_)at>  http://dotat.at/
DOGGER FISHER: SOUTHWEST 4 OR 5. SHOWERS. MAINLY GOOD.

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