When running the From Builder wizard to create the form, the Form Functions tab allows you to set the form to be emailed. on the Form Functions tab you can set the from and to email addresses.
After the form has been created, if you need to edit the email settings, open the server behaviors panel and double click the Universal Email server behavior.
If you did not configure the Form Functions tab to email the form when initially creating it, you can add Universal Email after the fact by going to WebAssist -> Create Email Message