Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Sat, 7 Apr 2007 22:59:10 -0400 (EDT)

The original message was received at Sat, 7 Apr 2007 22:58:38 -0400 (EDT)
from clmboh-mx-01.mgw.rr.com [65.24.7.10]

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

   ----- Transcript of session follows -----
... while talking to ms-mta-03-fn.nyroc.rr.com.:
>>> DATA
<<< 550 5.1.1 unknown or illegal alias: [email-masked]
550 5.1.1 <[email-masked]>... User unknown
<<< 554 5.5.0 No recipients have been specified.