Hi Shafi. You will know if the email is a simple alert from VizAlerts if it has a CSV file attached, and has a different footer at the bottom saying it came from VizAlerts. You should also be able to check the VizAlerts logs to see that it was processing the view and such. If it came as a normal Subscription, and wasn't actually sent from VizAlerts, you may simply need to ensure that the Schedule is disabled in Server.
Thanks so much Matt. Subscription schedule was not disabled. After disabling the schedule I was able to test successfully.