change this line:
$RecipientEmail = "".((isset($_POST["UserEmail"]))?$_POST["UserEmail"]:"") ."";include("WA_Universal_Email/WAUE_users_Registration_1.php");
to the admins email address:
$RecipientEmail = "admin@yourdomain.com";include("WA_Universal_Email/WAUE_users_Registration_1.php");