Email issue - suggested solutions required

[DirtyMonkey]

Can anyone suggest why my customers (customer) is unable to email my client and instead gets the bounce back below or how I can troubleshoot further (I'm new to Linux)?

psa v8.4.0_build84080515.15 os_Ubuntu 7.10
Linux 2.6.22-15-server

Thanks in advance, DM.

-----Original Message-----
From: MAILER-DAEMON@server001.rocketitsupport.com
To: prvs=10772c632c=anonymous@sd-taylor.co.uk
Date: 10 Jul 2008 15:32:11 +0100
Subject: failure notice
Hi. This is the qmail-send program at server001.rocketitsupport.com.
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.

<anonymous@smithieuk.co.uk>:

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

Return-Path: <prvs=10772c632c=anonymous@sd-taylor.co.uk>
Received: (qmail 24751 invoked from network); 10 Jul 2008 15:32:10 +0100
Received: from advantage-finance.co.uk (86.28.82.116)
by 141-55-84-80.rackcentre.redstation.net.uk with (RC4-MD5 encrypted) SMTP; 10 Jul 2008 15:32:10 +0100
Received-SPF: none (141-55-84-80.rackcentre.redstation.net.uk: domain at sd-taylor.co.uk does not designate permitted sender hosts)
DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=sd-taylor.co.uk;
s=MDaemon; t=1215700300; x=1216305100; q=dns/txt; h=DomainKey-Signature:
Received:Receivedate:From:To:Subject:MIME-Version:Content-Type:
Message-ID:In-Reply-To:References; bh=nb05xbThd4d4/MKDkX05xA9jGY
+7v0yeGUmq7gMfjHo=; b=e6hTL8LU1rhlvUU3t1mdIOHyWeSG/w5T9cp2ZCLNPN
Ldpgk95Gv47nvoQ9U/3GP0LKmVX0o7tFKT5+pdzlCYKPO3jIDCr1SBSM43t5hA9r
DPlLH+FlpOU4P8IAFrZnjMBzzdp9bQ4lAfFsWSHRguBcN2pDQIdn1v87W3FddI25
Y=
DomainKey-Signature: a=rsa-sha1; s=MDaemon; d=sd-taylor.co.uk;
c=simple; q=dns; h=from:message-id;
b=U4LKKd2oMgqAhFaB0nMds47WehbQ/wN30Dk8IwmZWsJVA0ha1pZNSpbCJs3R
MQIBH+SR0Cc31HgJ8PckjOHb7Z6ag7W+jRqNWDb8OfXB0ZNn+pHlCv8Fy
6SY4Pgh40FbxEXiMB5+llQ7Rq8IlaNxa34PgH7tqEo981RXX1qeS9w=;
Received: from WorldClient by advantage-finance.co.uk (MDaemon PRO v9.6.5)
with ESMTP id md50004326794.msg
for <anonymous@smithieuk.co.uk>; Thu, 10 Jul 2008 15:31:33 +0100
X-Spam-Processed: advantage-finance.co.uk, Thu, 10 Jul 2008 15:31:33 +0100
(not processed: message from trusted or authenticated source)
X-Authenticated-Sender: anonymous@sd-taylor.co.uk
X-MDRemoteIP: 127.0.0.1
X-Return-Path: prvs=10772c632c=anonymous@sd-taylor.co.uk
X-Envelope-From: anonymous@sd-taylor.co.uk
X-MDaemon-Deliver-To: anonymous@smithieuk.co.uk
Received: from [81.105.169.121] by sd-taylor.co.uk via WorldClient with HTTP;
Thu, 10 Jul 2008 15:31:29 +0100
Date: Thu, 10 Jul 2008 15:31:29 +0100
From: "Anonymous User" <anonymous@sd-taylor.co.uk>
To: "Anonymous User" <anonymous@smithieuk.co.uk>
Subject: RE: Wiis
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="_0710-1531-29-PART-BREAK"
Message-ID: <WorldClient-F200807101531.AA31290928@sd-taylor.co.uk>
X-Mailer: WorldClient 9.6.5
In-Reply-To: <!~!UENERkVCMDkAAQACAAAAAAAAAAAAAAAAABgAAAAAAAAALxPZMTvccE2YK2xhO73PK8KAAAAQAAAAdtT3vP5I5k696zz9YJ+MeAEAAAAA@smithieuk.co.uk>
References: <WorldClient-F200807101458.AA58370901@sd-taylor.co.uk> <!~!UENERkVCMDkAAQACAAAAAAAAAAAAAAAAABgAAAAAAAAALxPZMTvccE2YK2xhO73PK8KAAAAQAAAAdtT3vP5I5k696zz9YJ+MeAEAAAAA@smithieuk.co.uk>
X-MDAV-Processed: advantage-finance.co.uk, Thu, 10 Jul 2008 15:31:40 +0100

--_0710-1531-29-PART-BREAK
Content-Type: text/plain; charset="us-ascii"