Where do I specify the email on which I want to receive Portal delivery notification?

Under Create A New Portal page, Recipients field allows you to specify the email address(es) where you want to receive email notifications whenever an upload is done on the Portal.

The field is not visible to the client. Please note that if the field is left blank, there would be no emails sent about the activity in the Portal. However, all the transfers will be still accessed via the Packages > Received page.