Pure genious:
From: Mail Delivery Subsystem <bouncer(a)redhat.com>
To: <zaitcev(a)redhat.com>
Subject: Returned mail: see transcript for details
Date: Fri, 10 Apr 2009 13:00:24 -0400
The original message was received at Fri, 10 Apr 2009 13:00:23 -0400
from
vpn-12-123.rdu.redhat.com [10.11.12.123]
----- The following addresses had permanent fatal errors -----
<webmaster(a)fedoraproject.org>
(reason: 550 5.7.1 <webmaster@fedoraproject.org>... Relaying
denied. IP name lookup failed [172.16.27.26])
----- Transcript of session follows -----
... while talking to mx1.util.phx.redhat.com.:
>> DATA
<<< 550 5.7.1
<webmaster@fedoraproject.org>... Relaying denied. IP
name lookup failed [172.16.27.26]
550 5.1.1 <webmaster@fedoraproject.org>... User unknown
<<< 503 5.0.0 Need RCPT (recipient)
-- Pete