Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Fri, 22 Aug 2008 06:32:32 +0400 (MSD)

The original message was received at Fri, 22 Aug 2008 06:32:15 +0400 (MSD)
from CPE-60-231-153-125.static.qld.bigpond.net.au [60.231.153.125]

   ----- 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 [192.168.28.101]:
>>> DATA
<<< 550 5.1.1 <[email-masked]>... User unknown
550 5.1.1 <[email-masked]>... User unknown
<<< 503 5.0.0 Need RCPT (recipient)