Not asking for emails

I'm running a photo competition and have set up several times to ask for email addresses for each entry (mandatory). The setting never 'sticks' and I now have a vast number of entries without any way of contacting the entrant. How do you get the request email feature to work?

Hi, can you send the link to your contest to support@pollunit.com? Then we can have a look.
Please don't share the link here.
Kind regards
Philipp