Subject: [Gary] Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Wed, 9 Apr 2008 08:32:06 -0400 (EDT)

The original message was received at Wed, 9 Apr 2008 08:32:03 -0400 (EDT)
from pool-71-190-85-55.nycmny.east.verizon.net [71.190.85.55]

   ----- The following addresses had permanent fatal errors -----
<[email-masked]>
    (reason: 550 Requested action not taken: mailbox unavailable)

   ----- Transcript of session follows -----
... while talking to mainmail.seaerospace.com.:
>>> RCPT To:<[email-masked]>
<<< 550 Requested action not taken: mailbox unavailable
550 5.1.1 <[email-masked]>... User unknown
>>> DATA
<<< 503 Bad sequence of commands
>>> RSET
<<< 500 Syntax error, command unrecognized