How to find out which instance is sending me the dashboards ? This can happen in case users are receiving emails from unknown source that are not scheduled. (i.e Importing tenants on other servers without suspending the schedule)
If you have a scheduled dashboard which is configured to be sent once and you received the dashboard twice you can apply the below steps to know the incorta instance which is sending the dashboard:
1-Save the dashboard email to your PC
2-Open the email with any text editor, you will find the content of the file similar to the screenshot below
3-Search for the highlighted part which starts with "Received: from "
4-You will find the hostname of the analytics node which sent this dashboard and in our case it's "Azure-MigrateSupportMachine-SYS-225.localdomain" , you will also find the SMTP server info and in our case it's "(ec2-xx-xxx-xx-xx.us-east-2.compute.amazonaws.com. [xx.xx.xx.xx])"