The United States Postal Service (USPS) is the primary postal service provider in the United States, and is responsible for delivering mail and packages to every address in the country. While USPS does offer Sunday delivery for some types of mail and packages, the availability of this service depends on a number of factors.

USPS has traditionally been closed on Sundays, as this day is considered a non-business day. However, in recent years the organization has expanded its delivery services to include certain types of mail and packages on Sundays in select areas.
One of the main types of mail that USPS delivers on Sundays is Priority Mail Express. This is the fastest domestic shipping service offered by USPS, and guarantees delivery within one to two days. Priority Mail Express packages may be delivered to residential and business addresses on Sundays in many major cities across the United States. In addition, USPS may also deliver Amazon packages on Sundays, as part of a partnership between the two organizations.
It is worth noting, however, that Sunday delivery is not available for all types of packages or in all areas of the country. For example, regular mail delivery and other types of shipping services are not typically available on Sundays. In addition, Sunday delivery of Priority Mail Express packages may be limited to certain ZIP codes or specific delivery routes.
USPS also offers a service called “Premium Forwarding Service,” which allows customers to have their mail forwarded to a temporary address for a fee. This service may include Sunday delivery in some areas, although the availability of this service varies depending on the customer’s location and other factors.
Finally, it is worth noting that USPS delivery schedules may be impacted by holidays and other events throughout the year. For example, USPS may observe certain holidays on the following Monday or Tuesday, which may impact delivery schedules for the rest of the week. In addition, USPS may experience delays during periods of high volume, such as the holiday season.
In summary, while USPS does offer Sunday delivery for certain types of mail and packages, the availability of this service depends on a variety of factors, including the type of package, the customer’s location, and other logistical considerations. Customers who require Sunday delivery should check with USPS to determine whether this service is available for their specific needs.