Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Tue, 23 Sep 2008 10:07:42 +0400 (MSD)

The original message was received at Tue, 23 Sep 2008 10:07:39 +0400 (MSD)
from 189.58.232.125.adsl.gvt.net.br [189.58.232.125]

   ----- 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 main.iwan.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)