@songbird I never heard of INformed delivery. I signed up with UPS and always receive messages.
Informed delivery is by the Post Office. It shows you every morning via a picture the mail you re to receive and any packages that are coming you that day or the future (within 2-3 days) you will receive. UPS as a private company has their own.
Informed Delivery has never shown my packages. However, the vast majority give a tracking number. So I use these to let me know about when they will be delivered.