Newsletter subscription does not work

Hi,
I purchased the coupontheme (responsive as well) and have placed the mailinglist widget on my site. When you fill in your emailaddress, nothing happens. the subscriber is not put into the subcriptionlist and no confirmationemail is sent.
I also added the option to ask for a newsletter subscription when the customer clibks on a coupon. The pop-up appears and you can fill in your emailaddress. But then, nothing happens either.
HELP!