The administration system is set, by default, to automatically send an email license file whenever a customer record is added to it. If your business model prefers to send license information directly from your web site to a customer, or, some other internal management process, then you should disable this option so the administration system will NOT send any information to a customer when they are added to the system.
In an automated solution we would expect you to be using the LockLizard ecommerce integration module in order to display customer license files on a web page automatically. If you are using this method of license file delivery, then most likely, you would want to disable the sending of license file emails by the administration system.
To find out more about eCommerce integration, the manual is available on the downloads page.