SPF is a good start...
http://spf.pobox.com/

Do you actually have a info@gratingworks.com account? If not, don't
accept mail for invalid e-mail addresses.

ahgu wrote:
> somebody is using my email as the bounce-back return email.
> How do I avoid the problem?
>
> thanks
> Andrew
>
> X-Spam-Checker-Version: SpamAssassin 3.2.4 (2008-01-01) on xphotonics.com
> X-Spam-Level:
> X-Spam-Status: No, score=-0.0 required=5.0 tests=SPF_HELO_PASS
> autolearn=failed version=3.2.4
> X-Spam-Pyzor: Reported 0 times.
> X-Spam-Report:
> * -0.0 SPF_HELO_PASS SPF: HELO matches SPF record
> Received: from da1.hostingplus.nl (da1.hostingplus.nl [213.247.55.91])
> by xphotonics.com (8.14.1/8.14.1) with ESMTP id m38IYDjj098834
> for ; Tue, 8 Apr 2008 14:34:13 -0400 (EDT)
> Received: from mail by da1.hostingplus.nl with local (Exim 4.67)
> id 1JjIda-0004I1-RX
> for info@gratingworks.com; Tue, 08 Apr 2008 20:33:42 +0200
> Auto-Submitted: auto-replied
> From: Mail Delivery System
> To: info@gratingworks.com
> Subject: Warning: message 1JiuzE-0004HI-Pi delayed 24 hours
> Message-Id:
> Date: Tue, 08 Apr 2008 20:33:42 +0200
> X-Virus-Scanned: ClamAV 0.91.1/6671/Tue Apr 8 13:52:06 2008 on
> xphotonics.com
> X-Virus-Status: Clean
>
> This message was created automatically by mail delivery software.
> A message that you sent has not yet been delivered to one or more of its
> recipients after more than 24 hours on the queue on da1.hostingplus.nl.
>
> The message identifier is: 1JiuzE-0004HI-Pi
> The subject of the message is: *****SPAM***** Only Prestige
> The date of the message is: Mon, 07 Apr 2008 15:31:15 +0000
>
> The address to which the message has not yet been delivered is:
>
> advertising@winkelsingelderland.nl
> Delay reason: mailbox is full
>
> No action is required on your part. Delivery attempts will continue for
> some time, and this warning may be repeated at intervals if the message
> remains undelivered. Eventually the mail delivery software will give up,
> and when that happens, the message will be returned to you.
>
>