Are there options for user e-mail settings?

I want to build a forum for my users and it is to be totally anonymous, including e-mail address. As a matter of fact, I would prefer that e-mail was not even an option at all. All entries will be approved before posting.

I see that the e-mail is optional but wonder if I can remove it from the list.

What happens if someone enters an incorrect e-mail address. I realize it will not be deliverable but wonder if there will be any problems if several users enter a fake eddress. Do they pile up somewhere is the dead-e-mail office?