question on ptr rr

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