Hi Amit,
I don't think that AEM has a builtin notification mechanism. In enterprise environments it's quite likely that you already have a system, which monitors applications and escalates when certain thresholds are exceeded. There are also some good opensource tools out there (Icinga, nagios, zabbix, ...) which allow you to implement it quite easily.
On the AEM side you need to provide this data, which is easy when you can use JMX.
kind regards,
Jörg