Exchange 2013 DAG and Email Alert when Database Failover

Hi Experts,

I currently have a Exchange 2013 DAG running on 2 nodes (Windows 2012 R2) with a File Share Witness.  I have 3 databases and they are all seeded successfully to node 2.

My question is:

1.  How can I set up an email notification to inform me immediately when a Database fails over to node 2?

Could do with step by step instructions if at all possible. 

Kind Regards

GMSS