Andrew Thompson wrote: > I'm a little confused by this entry in my log: > > Received: from adsl-dynamic-pool-xxx.fpt.vn (unknown [118.71.113.83]) > by mx.myserver.com (Postfix) with ESMTP id DAB68800D3 > for <__use...@aktzero.com>; Thu, 23 Jul 2009 18:23:54 +0000 (UTC) > > If I `host 118.71.113.83`, I get: > 83.113.71.118.in-addr.arpa domain name pointer > adsl-dynamic-pool-xxx.fpt.vn. > > So where did the "unknown" come from, was that in the HELO? > > This is postfix-2.5.5, mx.myserver.com is my server, and I have not > knowingly customized any responses.
Postfix resolves first, the IP to a domain name (aka PTR record) AND then the acquired domain name to an A record. If one is not found, Postfix will log this as "unknown". When they do not match, it may do something similar too. Try doing "host adsl-dynamic-pool-xxx.fpt.vn" or "dig adsl-dynamic-pool-xxx.fpt.vn" to see for yourself. Brian
