Hi,
In emails we only have with or without taxes, not both. That's because emails are quite limited in width and displaying both with and without taxes prices in there wouldn't fit on the email and it would be completely ugly. Thus, when you use the "both" setting, it just display the price with tax in the emails. It's not a bug. It's the way we wanted on purpose.
If you want to display both, tt's quite easy to do actually.
Just remove the tax condition in the email preloads. For example the code:
if($config->get('price_with_tax')){
$t .= ' '.$currencyHelper->format($item->order_product_price+$item->order_product_tax,$data->cart->order_currency_id);
}else{
$t .= ' '.$currencyHelper->format($item->order_product_price,$data->cart->order_currency_id);
}
would become:
$t .= ' '.$currencyHelper->format($item->order_product_price+$item->order_product_tax,$data->cart->order_currency_id);
$t .= ' '.$currencyHelper->format($item->order_product_price,$data->cart->order_currency_id);