Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Wed, 24 Sep 2008 15:49:32 +0400

The original message was received at Wed, 24 Sep 2008 15:49:29 +0400
from [190.3.192.126]

   ----- The following addresses had permanent fatal errors -----
<[email-masked]>
    (reason: 550-Mailbox unknown.  Either there is no mailbox associated with this)

   ----- Transcript of session follows -----
... while talking to localhost:
>>> DATA
<<< 550-Mailbox unknown.  Either there is no mailbox associated with this
<<< 550-name or you do not have authorization to see it.
<<< 550 5.1.1 User unknown
550 5.1.1 <[email-masked]>... User unknown
<<< 503 5.5.1 No recipients