I am facing the same issue. I have uninstalled the plugin but still, I keep getting the email notifications. I have deleted the plugin files as well. I don't know where to look to.
Also, when I uninstalled the plugin, the files is still there. Seems like the uninstall is broken. Kindly please look into this. The email notification is very annoying now.
Furthermore, the default settings was to send a notification whenever it reaches 32mb. I changed it to 128MB, I still received notification when the memory usage reaches 32mb and above. After receiving a bunch of notifications I decided to uninstall the plugin. What surprises me is that, still I keep getting the annoying notification.