Rejection message when add new item on codecanyon

Hi all ,
i am new author in codecanyon. I received this message on my product review.

We have completed our review of “Simple PHPMailer, HTML & AJAX Contact Form” and unfortunately we found it isn’t at the quality standard required to move forward, and you won’t be able to re-submit this item again.

Demo Link:
I have added a proper document on submission for review.
Similar product on codecanyon:
If this product is in live then why is mine got rejected?
Can anyone help what is wrong with the quality?

Thanks in advance.