To send an alert notification via email, you must first set up the email notification channel.
To do so, complete steps 1-3 in Set Up a Notification Channel, then:
Enter the relevant details for the email notification:
From Shared With: Choose whether to apply this channel globally (All Teams) or to a specific team from the drop-down.
If you enabled Test notification, a test email will be sent.
You can now configure an alert to use email notifications.