Subject: Mail delivery failed : returning message to sender

From: Mail Delivery System <[email-masked]>
Date: Tue, 23 Sep 2008 07:10:29 +0200

This message was created automatically by mail delivery software on MAIL1.

A message that you sent could not be delivered to all of its recipients.
The following address(es) failed:

  [email-masked]
    SMTP error from remote mail server after RCPT TO:<[email-masked]>:
    host 192.168.64.81 [192.168.64.81]: 550 5.1.1 User unknown

------ This is a copy of the message-headers but with NO COPY OF THE MESSAGE-BODY. ------

From: =?koi8-r?B?7+/vICLpztTFzCI=?= <[email-masked]>
To: <[email-masked]>
Subject: =?koi8-r?B?8MXSxcjPxCDP1CDQzMHOwSDLIMTFytPU18nRzQ==?=
Date: Tue, 23 Sep 2008 13:10:25 +0800