The United States Postal Service (USPS), also known as the Post Office, U.S. Mail, or Postal Service, is an independent agency of the executive branch of the United States federal government responsible for providing postal service in the United States, its insular areas, and its associated states. It is one of the few government agencies explicitly authorized by the Constitution of the United States. As of 2023, the USPS has 525,469 career employees and 114,623 non-career employees.
The mail or post is a system for physically transporting postcards, letters, and parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid-19th century, national postal systems have generally been established as a government monopoly, with a fee on the article prepaid. Proof of payment is usually in the form of an adhesive postage stamp, but a postage meter is also used for bulk mailing.
A ZIP Code is a system of postal codes used by the United States Postal Service (USPS). The term ZIP was chosen to suggest that the mail travels more efficiently and quickly when senders use the code in the postal address.
Registered mail is a postal service in many countries which allows the sender proof of mailing via a receipt and, upon request, electronic verification that an article was delivered or that a delivery attempt was made. Depending on the country, additional services may also be available, such as:
A post office box is a uniquely addressable lockable box located on the premises of a post office.
A letter box, letterbox, letter plate, letter hole, mail slot or mailbox is a receptacle for receiving incoming mail at a private residence or business. For outgoing mail, post boxes are often used for depositing the mail for collection, although some letter boxes are also capable of holding outgoing mail for a carrier to pick up. Letterboxes or mailboxes use the following primary designs:
The United States Postal Inspection Service (USPIS), or the Postal Inspectors, is the federal law enforcement arm of the United States Postal Service. It supports and protects the U.S. Postal Service, its employees, infrastructure, and customers by enforcing the laws that defend the United States' mail system from illegal or dangerous use. Its jurisdiction covers any crimes that may adversely affect or fraudulently use the U.S. Mail, the postal system or postal employees. With roots going back to the late 18th century, the USPIS is the oldest continuously operating federal law enforcement agency.
Freepost is a postal service provided by various postal administrations, whereby a person sends mail without affixing postage, and the recipient pays the postage when collecting the mail. Freepost differs from self-addressed stamped envelopes, courtesy reply mail, and metered reply mail in that the recipient of the freepost pays only for those items that are actually received, rather than for all that are distributed. Freepost of preprinted cards issued by businesses is also different from postal stationery sold by postal administrations.
A multiline optical-character reader, or MLOCR, is a type of mail sorting machine that uses optical character recognition (OCR) technology to determine how to route mail through the postal system.
Remote Bar Coding System (RBCS), also called Remote Video Encoding (RVE) is a method used by the United States Postal Service to encode the address of letter-sized mailpieces that are not decipherable by a Multiline Optical Character Reader (MLOCR). When an MLOCR does not recognize a valid address on a letter, it sends an image of the mailpiece to a central RBCS (RVE) site where more sophisticated optical character recognition software is able to interpret many hand-written addresses using neural net and fuzzy logic algorithms. If this does not succeed, human operators visually examine the image and enter the address. In both cases, the data is sent back to the originating mail facility where mailpieces are then automatically matched back up with data through the use of a unique fluorescent barcode printed on the back during initial MLOCR attempt, and receive a POSTNET barcode representing the full address.
A Digital Postmark (DPM) is a technology that applies a trusted time stamp issued by a postal operator to an electronic document, validates electronic signatures, and stores and archives all non-repudiation data needed to support a potential court challenge. It guarantees the certainty of date and time of the postmarking. This global standard was renamed the Electronic Postal Certification Mark (EPCM) in 2007 shortly after a new iteration of the technology was developed by Microsoft and Poste Italiane. The key addition to the traditional postmarking technology was integrity of the electronically postmarked item, meaning any kind of falsification and tampering will be easily and definitely detected.
The Intelligent Mail Barcode (IMb) is a 65-bar barcode for use on mail in the United States. The term "Intelligent Mail" refers to services offered by the United States Postal Service for domestic mail delivery. The IM barcode is intended to provide greater information and functionality than its predecessors POSTNET and PLANET. An Intelligent Mail barcode has also been referred to as a One Code Solution and a 4-State Customer Barcode, abbreviated 4CB, 4-CB or USPS4CB. The complete specification can be found in USPS Document USPS-B-3200. It effectively incorporates the routing ZIP Code and tracking information included in previously used postal barcode standards.
Backscatter is incorrectly automated bounce messages sent by mail servers, typically as a side effect of incoming spam.
National Change of Address (NCOALink) "is a secure dataset of approximately 160 million permanent change-of-address (COA) records consisting of the names and addresses of individuals, families and businesses who have filed a change-of-address with the USPS". It is maintained by the United States Postal Service and access to it is licensed to service providers and made available to mailers. There are six licenses available including Full Service Providers and Limited Service Providers. The use of NCOALink is required in order to obtain bulk mail rates, as it minimizes the number of UAA mailpieces saving the mailer money and reducing the USPS's processing of this type of mail.
Mail sorting refers to the methods by which postal systems determine how and where to route mail for delivery. Once accomplished by hand, mail sorting is now largely automated through the aid of specialized machines. The first widely adopted mail sorting machine was the Transorma, first made operational in Rotterdam in 1930.
Knowledge-based authentication, commonly referred to as KBA, is a method of authentication which seeks to prove the identity of someone accessing a service such as a financial institution or website. As the name suggests, KBA requires the knowledge of private information from the individual to prove that the person providing the identity information is the owner of the identity. There are two types of KBA: static KBA, which is based on a pre-agreed set of shared secrets, and dynamic KBA, which is based on questions generated from a wider base of personal information.
A Microsoft account or MSA is a single sign-on personal user account for Microsoft customers to log in to consumer Microsoft services, devices running on one of Microsoft's current operating systems, and Microsoft application software.
Postal address verification is the process used to check the validity and deliverability of a physical mailing address. According to the United States Postal Service, an address is valid if it is CASS-certified, meaning that it exists within the comprehensive list of mailable addresses in their Address Management System. This is different from the credit card Address Verification System (AVS), which is the method used by credit card processors to authenticate ownership of a credit card by verifying that the account on the credit card matches the billing address on file. Credit card AVS does not determine deliverability of an address.
Package tracking or package logging is the process of localizing shipping containers, mail and parcel post at different points of time during sorting, warehousing, and package delivery to verify their provenance and to predict and aid delivery.
Mail Isolation Control and Tracking (MICT) is an imaging system employed by the United States Postal Service (USPS) that takes photographs of the exterior of every piece of mail that is processed in the United States. The Postmaster General has stated that the system is primarily used for mail sorting, though it also enables the USPS to retroactively track mail correspondence at the request of law enforcement. It was created in the aftermath of the 2001 anthrax attacks that killed five people, including two postal workers. The automated mail tracking program was created so that the Postal Service could more easily track hazardous substances and keep people safe, according to U.S. Postmaster General Patrick R. Donahoe.
