I am using the plugin and I have been trying to use the additional settings to redirect to a page after hitting the submit button. It used to work but now I stay on the page and get a regular message in a box with green borders.
I am using this:
on_sent_ok: "location = 'http://www.mywebsite.com/mypage';"
Plugin v. 3.3.2
Found the problem. It was a conflict with another plugin.