If you do, e-mail them immediately. Keep a copy of all mail you send to your instructor. You may want to cc yourself. That way you will know that the mail is being delivered, and you will also have proof that it was sent on time. Message your instructor on a regular basis, at least once a week.
Instructors appreciate knowing their students are attentive.
Be aware that e-mail messaging is a different medium. Choose your words carefully in a message. It is easy to sound brusque or even nasty when all the other person sees is a typed message. Humor is more difficult to get across in a message. An online course requires work completed every week of the course.