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Postfix doesn't get the PTR in a "from" connection

From: Dominique Blas (mlblas.net)
Date: Thu Jul 01 2004 - 16:43:59 CDT

Hi,

I don't like to post for such a problem that seems a bit more a local DNS problem rather than a Postfix problem but
I didn't find any misconfiguration in my DNS and a dig -x gives the good answer.

Postfix doesn't want to give (is not able to give, doesn't found, has no anwer from the name server) an answer for A PTR that exists.

A dig -x gives the good answer so why is Postfix unable to find it ?

Moreover it affects only the "from " not the "to'.
That is to say everything like
        connect from
        disconnect from
        NOQUEUE: reject: RCPT from
        lost connection after RCPT from
has no reverse resolution at all.
But the same host in a "connect to" line has its PTR listed in the log.
This excludes, from my opinion, a pb with the name server.

I'm going still further. On another machine with the same Postfix (2.2 20040621) and the same version of BIND (3.0-rc1 but a different configuration of course) Postfix finds correctly
the name of the "from" host and I can't see the difference between the 2 configurations involving any kind of resolution.

Absolutely speaking I would have nothing to do with this pb.
But, in this case, there is one host for which I want the PTR because this host is one of the hosts that are listed in the whitelist for my greylist.
And this whitelist works with domain name not ip addresses.

So, if you can find something, it would be great,

Regards,

db