Trello: Sending Unlimited Mails To Anybody With Easy Social Share Buttons Plugin

Hi, I want to talk about your ESSB plugin.When I was doing a research about it I saw that link " http://blog.trello.com/wp-content/plugins/easy-social-share-buttons3/public/essb-mail.php " When you navigate that link it says "message":"Error sending message!" But when you put the right parameters...