I wanted to use a service that was not invites, just for RSVping. So, the name "RSVpify" would suggest this was the right tool. However after I sent out invites I heard from some guests that they RSVPed, but I never got any responses. So, in summary this site/tool does not work. If you want to be sure you get RSVPs use something else. (It was free though, as they say you get what you pay for)