Reducing Event Alert notifications

[HunterG]

We would like to adjust our Event Alert email notifications so that we are still emailed when an event occurs initially, but not spammed w/ messages subsequently if the system stays down. Looking through the PBX settings options, we're only finding the option to remove the alert(s) entirely, which is not out intended goal. If it's down for another 15, 30 minutes, then another alert would be fine, but we don't want it alerting every 2-3 minutes. Hoping this is possible, thanks for any assistance!