Pop up to inform of new email message D7/Indy 10.0.52

I've just completed writing a mail client with Indy, and was wondering if
there is any way of knowing when a new msg arrives,while the app is running.
I tried using a timer to check msgs every second or so and it did not work,
infact it just froze the app. Surely there is someway of checking for new
msgs, without having to reconnect  the client?

What i basically want to do is to create a popup or make a sound when a new
msg arrives.

Thanks