yes, you could change:
//Start Mail Body
$MailBody = $MailBody . "";
$MailBody = $MailBody . ((isset($_POST["Subject"]))?$_POST["Subject"]:"");
$MailBody = $MailBody . "";
//End Mail Body
to:
//Start Mail Body
$MailBody = $MailBody . "Subject: ";
$MailBody = $MailBody . ((isset($_POST["Subject"]))?$_POST["Subject"]:"");
$MailBody = $MailBody . "";
$MailBody = $MailBody . "Phone: ";
$MailBody = $MailBody . ((isset($_POST["Phone"]))?$_POST["Phone"]:"");
$MailBody = $MailBody . "";
//End Mail Body