Redirect with existing email

Hello, thank you for your plugin is great.

I have only one problem. I’m using your plugin/form to let users subscribe in form and then get access to my site. The problem is that I want to redirect the user into the site even if he is giving the same email every time and don’t duplicate the email into the list.

is that possible ?
Thank you!

The page I need help with: [log in to see the link]