I had email as part of my sign up process. I got 2 emails entered by
remote people (although I was told that, at the time, I'd had only 1
"review" and the other might have been a spot check). I assume the
testers were told to use fake email addresses, but the ones I got
looked real enough. I didn't try them, obviously.
I didn't actually validate email. Just put the text box there and
required some input.
For the record, neither person completed the user sign up. Just got
through the first part.