members don't receive them, only the moderators and admins. again, they can go to account settings->notifications, scroll down and disable any type of notification they don't want to receive, this is a built in IPS feature, and a user setting, there really isn't a good way to "globally" disable it, and still allow it to work if the member wants it too, so they will have to disable receiving the notification if they don't want to receive them. i can do up a quick video on how to do this (again, this a built in IPS feature).