You can opt to receive email or phone notifications for alerts that fall into one of the three critical alert families.  Email notifications can be configured for non-critical alert families.  Alert families are predefined groups relating similar alerts together.  For example, critical alerts that have an impact on a Server where users will notice the problem (e.g. Exchange service stopped) are Critical User Impact Alerts. These alerts will be handled as highest priority by our technicians.  Some critical alerts, however, can have an impact on a Server but the users do not immediately notice the problem (e.g. Exchange takes longer than normal to read from the hard disk).  These Critical User Non-Impact Alerts can cause problems over time even though users are unaware they are occurring.  Critical User Non-Impact Alerts still need to be resolved at a high priority, but they can usually wait until the Critical User Impact Alerts are resolved first.