Email is just a TextBox question, the form has know way of understanding it as having a context of email, you could create multiple TextBox questions all named email and the form doesn't care, it will collect all the data and send it to you. The notification email is currently just for receiving notifications of form submissions, nothing more. It is not designed to be part of an email exchange process, but if the form has a TextBox question that captures an email address then the data is in the notification email and if you want to contact the person you can email them. Trying to make it aware of question content and intentions would be very difficult. We just send you the data and it is up to you how to use it, we make no assumptions about the data collected by the form.
Hope that makes sense,
Joe