Very often during site level power or network outages or during network maintenance multiple devices become offline at the same time causing multiple individual DOWN Email alerts to be sent at the same time.
Depending in the size of the site it can be well over hundreds or even thousands alert emails to be sent out to corresponding e-mail recipients configured for given site.
Starting from version 1.2.52 Nectus offers an option to aggregate multiple DOWN or UP email alerts into a single multi-device alert notification containing a list of all devices that became DOWN or UP within last monitoring interval.
To enable Alert Aggregation, go to Monitoring -> Global Monitoring Settings: “Alert” Tab
And Select “Aggregate multiple UP/DOWN Alerts” Option.