Go to Tools->Alerting & Reporting->Settings->VMware ESX.
Double-click VMware ESX/ESXi monitoring pack.
Click the Add Alert button in Monitoring Pack Settings window. Add Monitoring Event window displays.
Added events display on Alerts tab in the Monitoring Pack settings window. Double-click the selected event to define actions associated with it. Edit Alerting Script window displays.
Expand Predefined... menu to select one of already defined actions or click Add button to define a new one. The Add Action window displays.
Double-click to select the action. Edit Action Parameters window displays.