Its important to setup domain validation for security & SPAM prevention purposes.
1. Go to your form's settings panel.
2. In the General Sub Menu, Enter the domain from which you will receive the form submissions.
Reference GIF below,
How are submissions from other domains handled?
Currently in formX, if you submit from a different domain like localhost or any other domain, we will store upto 10 submissions and show you error message in the console regarding the same. Post that, formX does not record submissions from other domains.
Can we have the same form instance receiving submissions from multiple domains ?
No, this not currently available in the product. Do shoot your queries and feature requests to email@example.com.