The notifications are configured to be sent to the local root user. To send the alerts to an external user, an email alias for root is created. To switch off the alerting, you must:
1) remove the alias. In /etc/aliases find line like this:
and comment it out
2) edit /etc/asm/smartpop.yaml and search line in logging/handlers/email section. It should look like this:
Delete the line and you'll have to restart some services, at least the API:
monit restart api