Проблеиа с отправкой письма (Postfix)

[Ali]

From: "Mail Delivery System" <MAILER-DAEMON@domenname.ru>
To: <user@domenname.ru>
Sent: Tuesday, March 14, 2006 11:15 AM
Subject: Undelivered Mail Returned to Sender


This is the Postfix program at host ns.domenname.ru.

I'm sorry to have to inform you that the message returned
below could not be delivered to one or more destinations.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the message returned below.

The Postfix program

<User@cern.ch>: host cernmxlb.cern.ch[137.138.166.163] said:
550-5.7.1 Relaying denied. No reverse DNS configured for IP
<ip domenname.ru>.
550 See http://cern.ch/mmms/why.aspx?rdns=1&ip=217.106.86.254 for
more
information. (in reply to MAIL FROM command)

В чем может быть проблема. Настроен местный ДНС, почтовик...

[SashaAl]

1е. правильно ли ты написал адрес - существует ли такой юзер в том домене?
2е. на твоем мыльном серваке указан ДНС сервер? (/etc/resolv.conf)