e-mail visszapattanások

[Takács Zoltán]

Hali!
Pár napja egy-két helyről visszapattanak (vagy el se indulnak?) az 
e-mailjeink...
Mi lehet az oka?

első fejléc:
"This is a MIME-encapsulated message

Reporting-MTA: dns; mail.etszk.u-szeged.hu
Received-From-MTA: DNS; localhost
Arrival-Date: Wed, 16 Sep 2009 17:54:10 +0200

Final-Recipient: RFC822; titkarsag at mail.etszk.u-szeged.hu
Action: expanded (to multi-recipient alias)
Status: 2.0.0
Last-Attempt-Date: Wed, 16 Sep 2009 17:54:14 +0200

Final-Recipient: RFC822; schreinerne.gy at 3i.hu
Action: failed
Status: 5.7.1
Remote-MTA: DNS; mx1.invitel.hu
Diagnostic-Code: SMTP; 554 5.7.1 Client host rejected: cannot find your
hostname, [160.114.119.124]
Last-Attempt-Date: Wed, 16 Sep 2009 17:55:09 +0200"

második fejléc:
"From MAILER-DAEMON at mail.etszk.u-szeged.hu  Thu Sep 17 17:58:09 2009
Return-Path: <MAILER-DAEMON at mail.etszk.u-szeged.hu>
Received: from localhost (localhost)
    by mail.etszk.u-szeged.hu (8.12.8/linuxconf) id n8HFvn7u013498;
    Thu, 17 Sep 2009 17:58:09 +0200
Date: Thu, 17 Sep 2009 17:58:09 +0200
From: Mail Delivery Subsystem <MAILER-DAEMON at mail.etszk.u-szeged.hu>
Message-Id: <200909171558.n8HFvn7u013498 at mail.etszk.u-szeged.hu>
To: <titkarsag at etszk.u-szeged.hu>
MIME-Version: 1.0
Content-Type: multipart/report; report-type=delivery-status;
    boundary="n8HFvn7u013498.1253203089/mail.etszk.u-szeged.hu"
Subject: Returned mail: see transcript for details
Auto-Submitted: auto-generated (failure)
Status: R
This is a MIME-encapsulated message

Reporting-MTA: dns; mail.etszk.u-szeged.hu
Arrival-Date: Thu, 17 Sep 2009 14:37:12 +0200

Final-Recipient: RFC822; bobkoattila at t-online.hu
Action: failed
Status: 5.5.0
Last-Attempt-Date: Thu, 17 Sep 2009 17:58:09 +0200"

Hol nézzek szét?
Elvileg a DNS szerverünk volt piszkálva, de az mx-eket nem bántottam.