Hi,
You need to edit the emails via the menu System>Emails.
There, you need to look at the bottom "preload" section of the email where the data is formatted.
You'll see this line:
if(bccomp($data->cart->order_shipping_price,0,5) != 0){
that you can change to:
so that the shipping fee row is always displayed.
Similarily, you can change the line:
if(bccomp($data->cart->order_discount_price,0,5) != 0 || bccomp($data->cart->order_shipping_price,0,5) != 0 || bccomp($data->cart->order_payment_price,0,5) != 0 || ($data->cart->full_total->prices[0]->price_value!=$data->cart->full_total->prices[0]->price_value_with_tax) || !empty($data->cart->additional)){
to:
so that the subtotal amount is always displayed.