Mail form not sending anything

Hello everybody. I'm quite new to Grav. I'm building a site using th edeliver theme, but the form in contacts does not send anything, and does not show any feedback.
The mail plugin is set correctly and, by testing in the CLI, works properly. How can I solve this?
Thanks in advance

Have you checked the reference example here ?

Check first that the form is correctly storing the data, using the save action. Once this is ok, test the email action using https://mailtrap.io

Is the contact page a modular or a standard page?