I just downloaded this plugin and I have the same issue :(
I tried testing it on a blank page to not conflict with anything else on the page but no luck. I have no email sent, no message of email sent/not sent.
I also notice that clicking on the + sign, does not do anything. In fact, when on the first test page, i had placed this low in the page and whenever i clicked the + sign, i would be brought back to the top of the page. No biggie, but probably not the expected behavior.
I also checked and it works fine on the admin side, just not on the front end (where i need it most)
Any help would be appreciated.