To disable or enable an existing alert, access the Alerts page by clicking Alerts under Utilities in the lefthand navigation bar or hovering over the Notifications bell icon in the header and clicking the Manage Alerts link in the top right corner of the drop down.
From the Manage Alerts page, find the Alert you would like to disable/enable and click the toggle in the Status column.
A GREEN toggle indicates that the Alert is ENABLED and you WILL receive notifications. A GRAY toggle indicates that the Alert is DISABLED and you will NOT receive notifications.
You can also disable or enable an Alert by click the toggle at the bottom of the Edit Alert page.
At this time, there is no option to delete an Alert entirely.