Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Sat, 4 Apr 2009 07:53:15 +0200 (CEST)

The original message was received at Sat, 4 Apr 2009 07:52:28 +0200 (CEST)
from localhost [127.0.0.1]

   ----- The following addresses had permanent fatal errors -----
<[email-masked]>
    (reason: 550 relay not permitted)

   ----- Transcript of session follows -----
... while talking to dns2.iao.fhg.de.:
>>> DATA
<<< 550 relay not permitted
550 5.1.1 <[email-masked]>... User unknown
<<< 503 valid RCPT command must precede DATA