By default, any alerts you set will be sent to your email address as soon as possible. However, there are four possible email frequency settings:
As Soon as Possible - this setting will send you an email as soon as an alert is triggered
Daily - this setting will send emails once per day in the morning
Weekly - this setting will send emails once per week on Saturday morning
Never - this will turn off email alerts, but you can still view triggered alerts in your alerts inbox.