The old notification mechanism has been replaced with a new one in the shape of a Mailman mailing-list.
The old Movable Type notification facility did not require confirmation when subscribing to notifications, which could result in falsely subscribed users with no easy way to unsubscribe themselves. A Mailman mailing-list puts paid to that worry and also makes it possible for users to unsubscribe themselves at will.
So, if you want to receive a brief e-mail whenever an entry is posted to this blog, just subscribe to the mailing list.