To send the submission email to a different email address you will need to turn off the default notification and send setup a custom email instead.
1. Disable the custom summary
To disable email notifications on new submissions, go to "After Submission → Emails" in the form editor and toggle off "Send me an email summary on submission".
2. Add a custom email
On the same page (After Submission → Emails), click the "Add Email +" button under custom emails.
Enter in the desired recipient under the "To address", and add a subject line. For the "Content of email", select "Submission Summary" from the dropdown.
When you're ready, click the "Add Email" button to confirm the email address.
Save the form, and put through a test submission to verify that it is working correctly.