Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Thu, 23 Oct 2008 07:11:05 -0400

The original message was received at Thu, 23 Oct 2008 07:11:04 -0400
from adsl-pool2-81.metrotel.net.co [201.220.92.81] (may be forged)

   ----- 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)