What is a notifier

It is an email alert that is sent when you receive a submission on your form, you can update the email notifier and customize the text it contains as well as all the content in it. 

Here is a link with more info about email notifications and auto-responders: Explanation-of-Email-Notification-and-Autoresponder-Settings

Here is also a guide that will help you to set up an email notification on your form: Setting-Up-Email-Notifications

If you have any question, please let us know.