It is configurable by a parameter in my setup. An easy way to deal with it (unless someone really wants to do a lot of work) is to have login_id be an email if the site admin wants it. Otherwise you would need two sets of user_adds and etc.
I agree that email should be in person, if and only if it isn't forced to be unique as many people share email addresses. I will change that and try it out, shouldn't be too difficult.
I would also bet that any large site running OACS that requires email will have many bogus (i.e. bill@microsoft.com) email address, at least that has been my experience.
