Blocking Sessions/Users Alert

Hi All,
We have existing alert for all blocking sessions and users who holds lock/idle for more than 15 mins. Whenever we get alert, we send out mail to use to either log off or will kill the session after 5 mins.
Is there any way , we can automate this process of sending mail automatically to user who blocks session and idle for more than 15 mins to log off and kill automatically after 5 mins or so.
Thus will reduce the manual monitoring/intervention everytime

Any idea, would be greatly helpful

Thanks