Hi,
I tried this example and it seems to work:
<?php
$cusename="First Last";
$cusemail="user@domain";
$newaddress="receipient@domain";
$body = <<< EOBODY
<html>
<body>
Referrer: $cusename<br>
Referrer's Email: $cusemail<br>
<p>Our site has been recommended by your friend named above.
If you would like to enjoy the same price saving and pleasures
as your friend please visit our site at <a href="www..co.uk"><a href="http://www.s23.co.uk" target="_blank">www.s23.co.uk</a></a>. Thank you. </p>
</body>
</html>
EOBODY;
$headers = "MIME-Version: 1.0\r\n";
$headers .= "Content-type: text/html; charset=iso-8859-1\r\n";
$headers .= "From: webmaster@".$_SERVER['SERVER_NAME'];
$to = $newaddress;
$subject = "Site recommendation";
$extra = "From: webmaster@".$_SERVER['SERVER_NAME'];
mail($to, $subject, $body, $headers);
?>
Besides that the link is (<a href...) is invalid, just use one <a href...
Thomas