When an alarm assigned to a user is activated, the user immediately receives the notification according to its previous configuration (see here).
Such notifications are received by default on the platform Home Page, specifying the alarm in question and its status:
By clicking on "See all" button, you get the activation/deactivation record with all the details of the alarms notifications of the user:
If the email notification option has been activated, the user will receive also the it by this way.