Ninja Forms sends for every submission an additional report email

Hi there,

I recently switched to Ninja Forms for my contact forms. However, since I did, I get for every contact submission one additional email from the person’s email provider as a report.

So, if someone submitted the contact form with a gmail address, then I will also get an email from gmail that a request has been sent. Same with yahoo, etc.

Why is that and how can I get rid of that?

Thanks, Jana