Returned mail: see transcript for details‏

I keep getting the following message delivered to me, is there something wrong with the email set up on my shop?:

The original message was received at Wed, 19 Oct 2011 17:12:24 +0100
from web146.extendcp.co.uk [127.0.0.1]

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The following addresses had permanent fatal errors

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<dave@dampertech.co.uk>
(reason: 553 www.barracudanetworks.com/reputation/?pr=1&ip=79.170.44.146 )

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Transcript of session follows

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... while talking to spam.interdns.co.uk.:
>>> DATA
<<< 553 www.barracudanetworks.com/reputation/?pr=1&ip=79.170.44.146
550 5.1.1 <dave@dampertech.co.uk>... User unknown
<<< 503 RCPT first (#5.5.1)



--Forwarded Message Attachment--
To: dave@dampertech.co.uk
Subject: Your order No. C1L3X08 is now confirmed at www.spaldingfasteners.co.uk/
Date: Wed, 19 Oct 2011 17:12:24 +0100
From: enquiries@spaldingfasteners.co.uk

The problem is that the IP of your server is flagged as a spam server by barracudanetworks.
You should ask for ban removal on their website:
www.barracudacentral.org/rbl/removal-request/79.170.44.146

just done that thanks