If you enable Reminder Mail for an alert, a new email notification of that alert is generated on a schedule you specify as long as the alert has not been reset.
For example, if a Carbon Black File Reputation Unavailable Alert is triggered, email is sent immediately. If Reminder Mail is not enabled, no subsequent email is sent about this alert unless it is reset and the condition reappears.
If Reminder Mail is enabled and is set for 30 minutes, subscribers to this alert receive a new email every 30 minutes until connectivity is restored or the alert is reset.