System Alerts and Thresholds Triggers

[lucafabbri365]

Hello Community,

I'm writing this post to ask for a question related to System Alerts and Thresholds. In details I'd like to understand when/how these alerts are triggered.

1. I enabled these thresholds (SmartView Monitor > Global Threshold Settings) to send mail alerts at certain conditions:

1. CPU usage > more than 90%
2. Status connection > not connected
3. Synchronization state > equal not synchronized

2. I changed the command line script Run mail alert script (SmatConsole > Global properties > Log and Alert > Alert) to send mail to internal SMTP server:

3. These are time settings (SmatConsole > Global properties > Log and Alert > Time Settings) ?

Now the questions.

1. Firs of all, isn't necessary to "install policy" after the configuration above has been changed, right ? 
2. Focusing to the first threshold CPU usage, I'd like to know/understand the behavior behind alert triggering.
   If I set this threshold to the lower value 5%, when the alert will be triggered ? Every time the CPU usage, from a value lower or equal to 5%, passes to a value greater than 5% ?
3. Does the alert triggering also depend on fetching interval (point 3 above) ?

Does anyone have more information about it ?

Thank you,
Luca