Is it possible to be alerted as soon as a new transaction is registered on a specific property ?

Yes it is. Here is how to set up a property alert.

In the menu located at the top of the profile of the property you wish to get informed when a new transaction is registerd, simply click on the Alert button to activate the notifications.

From that moment on, you will get an notification by email as soon as a new transaction is registered on the property.  To remove the alert, simply click on the button again.