Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Tue, 27 May 2008 00:11:40 -0400

The original message was received at Tue, 27 May 2008 00:11:39 -0400
from 53.p3.svyaz-nt.ru [195.114.21.53]

   ----- The following addresses had permanent fatal errors -----
<[email-masked]>
    (reason: 553 5.3.0 <[email-masked]>... Invalid Rcpt - Sender is <[email-masked]>)

   ----- Transcript of session follows -----
... while talking to localhost:
>>> DATA
<<< 553 5.3.0 <[email-masked]>... Invalid Rcpt - Sender is <[email-masked]>
550 5.1.1 <[email-masked]>... User unknown
<<< 503 Need RCPT (recipient)