Ah, my bad; been a long time since I've had to do anything as an unregistered user, mis-remembered.

Looking at the code, we do require something that looks like an e-mail, for recovery purposes (I assume, that code predates me by a bit). It is not, however, verified.

It appears to do a basic regex to validate the e-mail address but does not require a confirmation e-mail to be sent to post comments.