How can I change the mail address of the receiver?

I presume you want to edit your form's email alerts to be sent on a different address, is that correct? First, I would like to suggest checking this guide to learn more about the basic settings of our email alerts: https://www.jotform.com/help/30-Explanation-of-Email-Notification-and-Autoresponder-Settings 

Now if you would like to change the recipient address for your specific email alerts, you can check this link: https://www.jotform.com/help/314-How-to-Properly-Add-Change-and-Test-a-New-Email-Recipient-Address 

Let us know if you need further assistance on this.