MINNEAPOLIS - Ever wonder what's going to come in the mail on a given day? The U.S. Postal Service has launched a service taking the surprise out of what's in your mailbox.

Informed Delivery is an optional notification service that provides residents with a daily digital preview of their mail. So how does it work? Eligible residents can opt-in to the program. Mail is then photographed during processing. Those who sign-up then receive an email containing the letter-sized images.

The service became available in the Twin Cities on March 10 and is being rolled out nationally April 14.

The USPS began testing the service in Virginia in 2014 and later expanded to five other states. Bob Dixon, the executive program director for Informed Delivery, told NBC News the feedback was "tremendously positive." A USPS survey found that nine out of 10 people who signed up for the service checked their Informed Delivery notifications every day.

Notifications are sent Monday through Saturday. The service is currently not available for mail delivered to P.O. boxes.

For answers to frequently asked questions about Informed Delivery, click here.