Hi,
Such emails are sent by default by HikaShop. If you don't get any emails, there is a miss configuration of either the emails settings of the Joomla configuration or the emails settings of the HikaShop configuration.
If you edit a customer in HikaShop, there should be an "email" button in order to contact the user that you can use to see if your website can at least send emails without any html.
In any case though, the best is to check your Joomla/HikaShop email settings with your hosting company as it's highly possible that they are not configured as per their requirements.