according to the fasthosts support page:
?article_id=65
you will need to pass the from address as an extra peramiter.
the from address you entered:
noreply@rendcem.co.uk
is this a valid email address for your domain?
what about the to address:
mai@rendcem.co.uk
is this a valid address?
in the universal email behavior, click the Envelope icon to go to the email server settings, make sure to check the option to include the from address as an extra parameter.
you will also need to add the ini_set code at line one of the page:
<?php ini_set("sendmail_from", "noreply@rendcem.co.uk"); ?>
i notice your page name contains a space, page names should not contain spaces, try renaming the page:
"contact rendcem.php"
to:
"contact_rendcem.php"
and change the form tag:
<form class="Sidebar_Default" id="SimpleContact_Sidebar_Default" name="SimpleContact_Sidebar_Default" method="post" action="contact rendcem.php">
to:
<form class="Sidebar_Default" id="SimpleContact_Sidebar_Default" name="SimpleContact_Sidebar_Default" method="post" action="contact_rendcem.php">