I have applied the inbuilt auto-responders on my form but it is not sending responses after someone fills a form

I checked your email alerts history but I could not find any issue with it. The history shows that all emails were sent properly. With this, please check your spam folder if all the emails would have landed there instead. 

You may also review your email activity history in order to understand/view the status of your forms' email alert deliveries. You can refer to this guide for more information: https://www.jotform.com/help/293-How-to-View-All-Your-Form-Email-History

If you have other questions, please let us know.