WHMCS's email templates determine the contents of the email messages that your WHMCS installation sends to your customers. You can customize all of WHMCS's included email templates or create your own Smarty email template files.
You can customize any of the emails that your WHMCS installation sends to your customers. WHMCS sends email whenever specific actions occur, and each action has an associated email template that you can customize from within the Admin Area.
You can restore the email templates that ship with WHMCS to their default contents. This can help you correct problems with customizations or resolve Email Template Not Found errors.