Thanks for the response, unfortunately after adding the code I get the following error:
Parse error: syntax error, unexpected ')' in /home/fhlinux194/g/guyedwardes.com/user/htdocs/WA_Universal_Email/mail_PHP.php on line 254
Which is the replaced line of code suggested.
P.S. The host has provided the following knowledgebase article to assist if that helps: ?article_id=65