I have runbook created in azure automation for getting the list of Vm's running. I want to know if there is a way to add a email endpoint for sending the response of this runbook
You can't send directly from Azure Automation natively, you will need to either use SendGrid or a Logic App to send the email.
https://learn.microsoft.com/en-us/azure/automation/automation-send-email
https://learn.microsoft.com/en-us/azure/app-service/tutorial-send-email?tabs=dotnet