Hi,
There is indeed no option to disable that.
That would require the development of a plugin to do that properly.
As a quick and dirty solution, you can remove the code:
if(!empty($user_email)) {
if(HIKASHOP_J30) {
$mailClass->mailer->addReplyTo($user_email, $user_name);
} else {
$mailClass->mailer->addReplyTo(array($user_email, $user_name));
}
}
in administrator/components/com_hikashop/classes/order.php but note that you'll loose the change when you update HikaShop so you'll have to redo it after the update.