Jason, I have reduced the instances of Server Validation Behaviour to just one and included multiple server validation instances in that one as you suggested. I have removed the redirect to index.php. The Universal Email is configured to use 'real' email address in the From field and To Field.
I am using SSL SMTP with authentication and have the correct credentials for Hostgator Server (which incidentally works perfectly with the double opt-in registration -Security Assist Wizard created pages) but the email will not send.
Please see attached revised php file.
What I am doing wrong?