Hello Giulio Curà,
Sorry for late reply to this,
If i'm not getting wrong meaning of your issues, you're asking about that email notification right?
If yes, i have checked in your backend Easydiscuss > Setting > Maintenance > Send email when the page loads - YES (You should set to YES)
Mean when the user load your site that time, the Easydiscuss will process send the email notification to the user.
see my screenshot result :
http://screencast.com/t/tytQ5kpIx
If you would like the email notification automatically send out every 5 minute, you have to set up the cronjob for run this.
Documentation LINK :
http://stackideas.com/docs/easydiscuss/cronjobs
If you need further assistance, please provide us with your Cpanel access so we can help you configuration with this.