I tried the following test in my testing environment.
1) Configure [Advanced Email] - [All critical Events]
2) Disconnect power supply cable of PSU1.
3) Waiting for recieve the email notification with monitor smtp server's queue.
4) Connect the cable.
5) Repeat step 2) - 4) several times while watching my smtp server.
Notification Email seems to be sent every 5 minutes.
I think that ASC checks hardware events every 5 minutes. And if an event happened between the check intervals, ASC sends it by an email.
Am I correct?
Thanks and Regards,