Enable ability to require that someone shares their email when depositing a File Request.

Today, I can only require someone to login to their Box account OR use a text field that says email, but I want a field SPECIFICALLY called email inside of File Request, so that I can trigger a Box Relay workflow to notify the email of whoever triggered the workflow (e.g. if a submission is denied, I want to notify them that it was denied and to include why........ if a submission was approved, I want to notify them that it was approved and to include why).