Go to Admin > Settings > Customers

On the Customers (End-users) settings page, you select the settings that affect how your users access and use your Zaidesk. All options here determine how open or restricted your Zaidesk is to your end-users.

The first option “Web Portal” is about enabling the zaidesk support to their end users. If this option is disabled the other two portal related options are automatically disabled. But if the web portal is enabled then you can choose the other options to be displayed on the web portal.

If "anybody can submit new ticket on portal" is enabled that anyone can submit ticket but if this is disabled then only registered users can submit ticket through their portal.

The third option is User "Activation Email" that will send automatic activation email to coming end users. If this is not enabled then the activation email will be sent by admin/agent manually.