Membership not checking for valid email address format?

Hi! I'm using the Membership plugin, WP3.3 and Buddypress. Everything is up to date.

It appears that the registration form doesn't check that the email address is in a valid format, so I've had a couple of users sign up without entering an email address (the field is still required, but you can put anything you like in there).

I'm absolutely happy to add a bit of my own code to do this but thought I'd best check to see if it was something I was missing that could be corrected within the existing structure before I start making changes.

Thanks for a great plugins, by the way! I'm very happy with my subscription!

(Edited for clarification)