what use is reminders?

Hi there,

I'm currently trialling ServiceDesk Plus and have a question about reminders.
I've seen the manual to manage it (create/edit/delete/etc) but still wondering how it actually supposed to be used.

My understanding was that when we set up a reminder, put in the date and time, there should be some kind of notification on the specified time without us actually going to the Quick Actions > My Reminder(s).
But so far, nothing.
No pop up box or anything. I even tried to log out and log in again hoping that there's a notification box displaying my reminders, but none so far.
I haven't set up the mail server config yet so not sure if it supposed to send out email with reminders on them.

Unless I missed something here?

Thank you for your advice.