Admin and end user alerts Notification Email Alert Notifications from CAS are sent from mandrillapp.com domain

This Articles explains about Admin and end user alerts Notifications from CAS

You will receive Admin and end user alerts from mandrillapp.com domain. This is currently valid behavior and its a legit mail. This behavior will change sometime in the future BUt unfortunately we don't have an ETA. 

Example of admin and end user alerts Notification from CAS:-