Informed Delivery

Informed Delivery is a feature offered by the United States Postal Service (USPS) whereby consumers can digitally preview incoming mail and manage packages scheduled to arrive soon.
Consumers that sign up for Informed Delivery can digitally preview their mail and manage packages scheduled to arrive soon via email notification, online dashboard, or mobile app. Users also have the ability to interact with digital content provided by business mailers (e.g., special offers, related links) directly from Informed Delivery.
Exterior images are only provided for letter-size mailpieces that are processed through USPS automated equipment. Some mailpieces (e.g., catalogues, magazines, larger envelopes) are not imaged by USPS automated equipment and will not appear in Informed Delivery notifications. Users can also receive USPS Tracking updates for incoming packages, provide delivery instructions, manage notifications, and schedule redelivery directly from Informed Delivery. The feature also allows consumers to indicate if specific items in the Informed Delivery notifications are not received.
Availability.
Informed Delivery was first made available as a pilot project in a few ZIP Codes in 2014, and in 2017 was expanded to the majority of ZIP Codes across the United States. As of January 2019, there were 14.9 million users and counting.
Reception.
According to an April 2018 user survey (8,631 respondents in 5,784 ZIP Codes), 89% of respondents are satisfied or very satisfied with the feature. 93% would recommend Informed Delivery to friends, family, or colleagues.
Security and privacy.
Some consumers have expressed concern that Informed Delivery could be misused by stalkers, abusive ex-partners, private investigators, and identity thieves. 
The Postal Service takes measures to ensure the security and privacy of consumers’ mail. Because Informed Delivery offers increased visibility into both mail and packages being delivered to an individual’s address, USPS follows industry best practices to verify identity, including the use of a mail-based verification letter.
According to Krebs on Security, Informed Delivery uses a form of authentication known as knowledge-based authentication (KBA) to verify that people signing up truly live at that address. KBA authenticates users by asking them a series of multiple choice questions that, presumably, only the user would know the answer to. However Krebs has criticized KBA because in his view many of the questions can be answered easily by an attacker accessing social media. Informed Delivery executive program director Bob Dixon had indicated that security would be improved by January 2018 by sending a letter confirmation when someone signs up. Mail-based verification letters were implemented by USPS in January 2018, and are sent after sign-up to the account address to give the residents the opportunity to remove the Informed Delivery account if desired.