Explanation

Step 1: Create a resource group containing the critical resources.
In step 2 the action group should be created within this Resource Group.
Step 2: Create an action group for alerts to email addresses.
You configure an action to notify a person by email or SMS, they receive a confirmation indicating they have
been added to the action group.
The rate limit thresholds are:
SMS: No more than 1 SMS every 5 minutes.
Voice: No more than 1 Voice call every 5 minutes.
Email: No more than 100 emails in an hour.
Step 3: Monitor service health for incidents and action required notifications
An action group is a collection of notification preferences defined by the owner of an Azure subscription.
Azure Monitor and Service Health alerts use action groups to notify users that an alert has been triggered.
References:
https://docs.microsoft.com/en-us/azure/azure-monitor/platform/alerts-rate-limiting