How can users decide for themselves if they want the daily or weekly digest or the ‘immediate’ notification?

How can users decide for themselves if they want the daily or weekly digest or the ‘immediate’ notification?

Once I enable the email digest in Admin > Site > Email options, the option to receive immediate notifications of new forum posts or new blog posts seem to disappear. 

Before (without daily/weekly digest, with the widget)

After (no option to optin for notifications, only for daily or weekly digest or none at all).