No verification

See FAQ > The spinning arrow icon shows up once I submit a form, but then nothing happens.

Thank you Takayuki for your response, but this doesnt resolve my problem. I m using your plugin in two websites, it’s fast, it’s simple, i just love it, but I cant deactivate my other plugins neither I can go back to default theme!

If those tests are not possible in your production site, you should think of making a testing site with the completely same versions of WordPress, theme and plugins used in the production site and try testing on it.