yes, it was probably made by people who only know how to use front page.
you can put the form itself in an if/else statement:
PHP Code:
if($_POST){
// ALL THE MAIL CODE ABOVE GOES HERE
echo "Thank You, your message will be ...";
}else{
echo "<form method=post action=...>";
// the rest of the form here
}
?>
that way it will show the form 1st, then when the post, it just says thank you and sends the email.