YouTube has recently changed the
settings for notifications. When you subscribe to a channel, there's a box that says "Send me all notifications for this channel".
The settings page has a new label for the email digest checkbox: "Occasionally notify me of new videos and activity from my subscriptions" and you can choose if you want email notifications, mobile notifications or both email and mobile notifications.
Mobile apps for Android and iOS have a notification section in the settings, which lets you disable or enable notifications, customize notification types (subscription activity, recommended videos, comments and replies) and also see all your notifications.
