Delay in receiving e-mails

Hi, I discovered a trouble with e-mails from Form Manager. The thing is, there is a time gap between the time the form is filled out and submitted and the time I receive it. The time gap is about 3-4 days. The form is here: https://aida-style.com/contact-me/. I tested it few times and this issue is all the time there.

Is this the problem with hoster? Where should I look for solution?

Please advice…

Thank you very much in advance,
Natalie

https://www.ads-software.com/plugins/wordpress-form-manager/