question on ptr rr
Andrew - Supernews
andrew at supernews.net
Sun Feb 8 22:44:15 UTC 2004
>>>>> "Chris" == Chris Adams <cmadams at hiwaay.net> writes:
> Once upon a time, Andrew - Supernews <andrew at supernews.net> said:
>> If you're going to get picky about HELO names, then it's better to
>> require that the HELO has an A record pointing to the connecting IP,
>> rather than look at PTR.
Chris> That isn't necessarily a good test;
There _is_ no good test, which is one reason why the RFC says
unequivocally "don't do that".
Chris> for example, we've got a couple of servers in a cluster. One
Chris> IP pointed at the cluster is mail.hiwaay.net, and that is what
Chris> is used in HELO/EHLO when making outbound connections, but the
Chris> connections don't come from that IP. They come from the
Chris> cluster member's IP so that when we get a complaint with
Chris> sending IP, we don't have to look through the logs for the
Chris> whole cluster to find the offender.
In that case you'll fail _any_ sort of verification on the HELO, so
it doesn't really matter whether the recipient uses the PTR or the A
record.
--
Andrew, Supernews
http://www.supernews.com
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