All of the sender’s emails should be grouped together. Select the first email you want to delete. Scroll all the way to the end of the list and choose Remove. Hold Shift and select the last email. Select Delete from the drop-down menu that appears when you click on an item.
Click Manage Internet from the Services page, then Select a Service and Delete a Device. Select an option to delete your device: Select Remove to remove your device from the list of registered devices; or, Click Rename to edit your device name; or, Click Reactivate if you’ve previously uninstalled it. To remove your device from the list
Select Delete Messages from the Server, then select when you’d want your mail removed from the server.
Call customer service at 1-800-Xfinity or 1-800-Comcast to have your account deleted.