Hi,
The email is sent automatically by HikaShop when the order is confirmed.
Are the orders confirmed ?
If not, then the issue is probably that your payment gateway is not sending back payment notifications to HikaShop.:
www.hikashop.com/support/documentation/i...or.html#notification
If yes, then the email is sent by HikaShop via your email server. Either the Emails settings of the HikaShop/Joomla configurations are not set properly for your email server, or there is a problem with your email server. In that case, you want to contact your hosting company and check your Emails settings with them and see if there are any logs of the email server about an issue with the order status notification emails.