Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Wed, 15 Oct 2008 19:41:24 +0400 (MSD)

The original message was received at Wed, 15 Oct 2008 19:41:23 +0400 (MSD)
from 3E333A88.dslaccess.aol.com [62.51.58.136]

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