Hi,
It does. The emails have to be enabled or they won't be sent.
If you disable them, your customers won't get them, none of them.
But the fact that the emails are enabled doesn't mean that the emails will be sent and received all the time for everyone. There are other factors.
So you say that the way it is setup now, one customer received the email and not the other one ?
How do you know ? Is it because the customer told you ? Or because you didn't see it in the Email history of HikaShop ?
Check that the emails are in the Email history (menu Users>Email history). If you see it there, it means that the email has been sent by HikaShop. If the customer didn't receive it, it means that either the email server couldn't send/receive it or that it went in the spam folder.
If it's the spam folder, then you need to check your emails with mail-tester.com
If it's an email server issue, you need to seek help with your hosting company. Provide screenshots of the settings of the email section of Joomla and of the email detail screen in the Email history of HikaShop and ask them to check their email log for that email because the recipient didn't receive it. They should be able to tell yuo what's going on.