DataBase Mirroring alerts


In one of our customers the database mirroring was already configured. After long years they came to us and asking to configure the database mirroring alerts. The alerts needs to come to their mailid if some things happens to the mirroring.
In the server the database mail id is already configured for failure jobs.
Now i need to configure same mailid for mirroring alerts also.

I am completely lost in touch with mirroring after always on came into the market.
Can anyone please help me to configure db mirroring alerts in the same server.

what exactly i need to follow to set mail alerts for current mirroring setup.