I have my own email address as the receiver, I received an email notification with the persons request, but I dont know how to contact that person back.

If you get a message from a Classmate inside the system: Simply click reply, and you can communiate with the Classmate directly inside the system.

If you get a message from somebody outside of the system (i.e. you've chosen to leave your Profile public so you can receive non classmate communications) then you'd need to click on "Reply" in your own email program where you received the message. If a message comes in from the outside, it has nothing to do with our system anymore and you'd need to communicate using your own email program.