Easy to check and see from this window
From a map list or map, go Window – Device List
This is every device on every map you are monitoring and sending alerts on
There are 3 icons in upper left hand corner of window
The middle icon is your alert settings for each device
When you click on it, a drop down text box appears with all alerts defined
Click on the drop down box and select the alert that is sending
This will show you all the devices that are using that email alert
To stop sending, just uncheck the box on the alert of that device
There also delay, repeat and count selections that you can change
Perhaps the alert has been set to repeat forever
From the alert you should be able to tell what device is getting monitored