How do I remove Free Shipping: $0.00 from email?

Hi
I am currently working on a site where all products are virtual. I have managed to remove all reference to shipping on the site but I can't figure out how to get rid of the Free Shipping: $0.00 that shows in the order confirmation email. I have tried with and without the free shipping module activated without any luck.

The site is being used as a course booking site so there is no need for shipping at all.

Any help greatly appreciated.

Thanks

I think I have it worked out. I was looking at this thread http://www.zen-cart.com/showthread.php?111307-Removing-free-shipping-text-from-virtual-product-total and at the bottom of the first page it has this bit of code

function process() {
      global $order, $currencies;
     if ($_SESSION['shipping'] == 'free_free') {
        $this->output[] = array('value' => $order->info['shipping_cost']);
                                }
     else {
         $this->output[] = array('title' => $order->info['shipping_method'] . ':',
                                'text' => $currencies->format($order->info['shipping_cost'], true, $order->info['currency'], $order->info['currency_value']),
                                'value' => $order->info['shipping_cost']);
                                }
    }  

but I wasn't sure where to put it. I have replaced this code in ot_shipping.php

function process() {
      global $order, $currencies;

        $this->output[] = array('title' => $order->info['shipping_method'] . ':',
                                'text' => $currencies->format($order->info['shipping_cost'], true, $order->info['currency'], $order->info['currency_value']),
                                'value' => $order->info['shipping_cost']);
    }

with the one above and it seems to be working. So hope this will be a bit clearer to someone else trying the same thing.

Thanks