Well, if the rules demand you have a working email to win, then there will be no need to ask those people since their images ideally should not be presented to the jury ;)
(But I do not think the jury tool has support for that.)
/Jan
You need to have an address but nothing prevents kind people to warn you that you've forgotten to enter it before the end of the competition ;)
@pigsonthewing I was thinking to people that are new, come once, maybe twice, will never show up again and won't see a message left on their talk page if it's not left short after their first uploads.
But if you think it doesn't worth the effort to develop something, I'll try to do it on my part and will let you know.