Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Mon, 11 Aug 2008 16:08:57 +0300 (EEST)

The original message was received at Mon, 11 Aug 2008 16:08:55 +0300 (EEST)
from 200-148-233-38.ensite.com.br [200.148.233.38]

   ----- The following addresses had permanent fatal errors -----
<[email-masked]>
    (reason: 550 5.1.1 User unknown)

   ----- Transcript of session follows -----
... while talking to [10.200.0.7]:
>>> DATA
<<< 550 5.1.1 User unknown
550 5.1.1 <[email-masked]>... User unknown
<<< 503 5.5.2 Need Rcpt command.