If a monitored site goes down during a defined maintenance window period and then remains down, we do not see an alert triggered. Why does this occur?
The current version of ASM does not consider maintenance mode when determining when to alert a user. So if a monitor alerts in maintenance, it gets suppressed and will not alert again unless one of the following conditions is meet....
-the monitor has a successful check and then renters the error state
-the "Remind me again after an alert in" field is set.
The "Remind me again after an alert in" is the best way to ensure continuous alerting. This can be set in the monitor's configuration under the Alerting tab.