Subject: [Gary] Returned mail: see transcript for details

From: [email-masked] (Mail Delivery Subsystem)
Date: Sun, 20 May 2007 16:53:30 +0200 (CEST)

The original message was received at Sun, 20 May 2007 16:53:29 +0200 (CEST)
from mail1.prosiebensat1.net [193.28.192.43]

   ----- The following addresses had permanent fatal errors -----
<[email-masked]>
    (reason: 550 5.1.1 <[email-masked]>... User unknown)

   ----- Transcript of session follows -----
... while talking to leipzig-mail.transfer.sevensys.de.:
>>> DATA
<<< 550 5.1.1 <[email-masked]>... User unknown
550 5.1.1 <[email-masked]>... User unknown
<<< 503 5.0.0 Need RCPT (recipient)