Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Wed, 15 Oct 2008 09:11:05 +0600 (YEKST)

The original message was received at Wed, 15 Oct 2008 09:11:03 +0600 (YEKST)
from [123.9.167.74]

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

   ----- Transcript of session follows -----
550 5.1.1 <[email-masked]>... User unknown