Unauthorized use of my email

[gd]

I'm getting lots of undelivered emails and im not the one sending them out. It looks like to me that someone is sending spam email and are using my email as the return address. Take a look below any ideas hot to stop it? my email domain email lockum@lockum.com
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Return-path: <>
Envelope-to: lockum@lockum.com
Delivery-date: Wed, 27 Aug 2003 20:55:47 -0400
Received: from [207.44.226.4] (helo=plesk.rackshack.net)
by www6.pcdc.net with smtp (Exim 4.20)
id 19sB4k-0004KD-UF
for lockum@lockum.com; Wed, 27 Aug 2003 20:55:46 -0400
Received: (qmail 26112 invoked for bounce); 28 Aug 2003 02:43:44 -0000
Date: 28 Aug 2003 02:43:44 -0000
From: MAILER-DAEMON@plesk.rackshack.net
To: lockum@lockum.com
Subject: failure notice
Message-Id: <E19sB4k-0004KD-UF@www6.pcdc.net>

Hi. This is the qmail-send program at plesk.rackshack.net.
I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

<info@cashblast4us.com>:
This address no longer accepts mail.

--- Below this line is a copy of the message.

Return-Path: <lockum@lockum.com>
Received: (qmail 25828 invoked from network); 28 Aug 2003 02:43:14 -0000
Received: from cox-66-210-188-34.coxinet.net (HELO DALLAS-GI) (66.210.188.34)
by 207.44.226.4 with SMTP; 28 Aug 2003 02:43:14 -0000
From: <lockum@lockum.com>
To: <info@cashblast4us.com>
Subject: Re: Your application
Date: Wed, 27 Aug 2003 20:02:40 --0500
X-MailScanner: Found to be clean
Importance: Normal
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-MSMail-Priority: Normal
X-Priority: 3 (Normal)
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="_NextPart_000_01199DFE"

This is a multipart message in MIME format

--_NextPart_000_01199DFE
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: 7bit

Please see the attached file for details.
--_NextPart_000_01199DFE
Content-Type: application/octet-stream;
name="wicked_scr.scr"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
filename="wicked_scr.scr"
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[porcupine]

This isn't being sent from anywhere on our network, so you can't do much about it. Looking at the attachment (.scr), it's clearly one of those internet worms that just spoofs everyone in the infected computers address book and sends out emails at random trying to get them to open the infected files. I'd just ignore it, as it has no relavence on your email address.