sender and recipient

You might be referring to how you can set up the email notifier on your form. 

Here's a guide that can help you: Setting-Up-Email-Notifications.

Here's another guide that will help you fully understand the details of the notifier.

Notification-Autoresponder-Email-Details

If this is not what you mean, kindly give us more information and we will be glad to help you further. Thank you.