Hi Stefano this is from the Easy Sign Up plugin description:
Easy Sign Up is a very simple two field form that collects the name and email.
Once filled out it redirects your user to a web-page of your choosing.
You’ll be notified by an email containing the name and email address from the form.
This data is not stored by the plugin – but there is an extra for that.
Your user will receive an email thanking them for the submission.
You can customize this email in the setting panel in your Dashboard.
For your email issue: This comes from the support forum.
Issue resolved this Post is for anyone else who may run into the same issue:
Looks like the ISP or Email Service Provider was blocking the site owners Notification Email.
Fixed by changing the Notification Email Address in the settings page for the Easy Sign Up Plugin.
Other Possible fixes could be:
1) Check your Spam folders
2) Add the email address, and if possible the IP address of your website to your “Safe List”. Your Email Provider should provide you with instructions on how to do this.
For Context see this link: https://support.beforesite.com/topic/easy-data-causing-problem