I have the same problem. I’ve used the plugin a year now – and suddenly (after the latest update of WP) I tried to submit the form while I had WordPress open – and everything was okay. I were forwarded to the success-message and the email was sent – But after I closed WordPress – In clicked the send button in the form – the wheel kept turning – just like nothing has happened – but the emails are sent. The customer cannot see that the submit was successfully because the software doesn’t forward the customer to the thank you page.
