Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Tue, 26 Aug 2008 19:45:22 +0400 (MSD)

The original message was received at Tue, 26 Aug 2008 19:45:21 +0400 (MSD)
from p5B2F2C9C.dip0.t-ipconnect.de [91.47.44.156]

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

   ----- Transcript of session follows -----
... while talking to enzyme-e-204a-2.chem.msu.ru.:
>>> RCPT To:<[email-masked]>
<<< 550 User unknown
550 5.1.1 <[email-masked]>... User unknown