Mail.XML™ can be viewed as an extension of Mail.dat in an XML, Web Services format.  About Mail.XML

The focus of Mail.dat® has, and will continue to be, the full description of a mailing job and related data. The traditional Mail.dat® fixed-record specification is very well suited to conveying full and updated data. However, there are instances where full data per job is not necessary and there are also many of mail processes that encompass mail product and information from more than one Mail.dat® job. To handle these situations, the Mail.dat® Editorial Committee has established the Mail.XML specification. Mail.XML is geared towards transactional two-way conversational communication in a near real-time environment.

The Mail.XML Specification is bringing a paradigm change to the industry by increasing business function specific B2B (Business to Business) communication within the industry that supports automation and in the end enables cost avoidance and higher profits through improved competence and effectiveness of communication. Mail.XML is designed to increase efficiency and lower costs by removing many manual data entry processes and enabling quick near-real-time communication between business partners. Mail.XML currently supports appointment scheduling supply chain communication, support for eDocs (postage statements and qualification reports), co-palletization support, and data distribution support where the USPS can make Full Service, StartTheClock, Container scan and Full Service compliance information available to the customers. The core focus of Mail.XML is communication between industry members and from industry to the final mail processing and delivery organization that delivers the mail to the end consumer, e.g., USPS. Also, USPS is making all communication back to the mailers accessible and available through Mail.XML.


Mail.XML Version 1.0 (previously known as the Transportation Messaging Specification) was originally focused on transportation and drop shipment processes, allowing customers to create, update, and cancel appointments and content, and receive closeout data. Since the initial publication, 18 more versions of MailXML have been published and the scope has broadened to include data distribution (EDoc), mailing messages and informed visibility. Latest versions of MailXML supports USPS™ Informed Visibility.

Mail.dat vs. Mail.XML

Mail.dat stores complete information about a mailing as a database. Prior to Mail.XML, the complete dataset was interchanged between the list house, printer/manufacturer, trucking company and USPS.Mail.dat will not be replaced by Mail.XML.

Mail.XML provides an alternative to exchanging the entire Mail.dat database. Mail.XML adds a new light-weight transaction messaging mechanism between mail owner, list house, manufacturer/printer, logistics company and the USPS. Mail.XML handles real-time communication across the mailing supply chain. In addition, Mail.XML provides for extended B-2-B functionality that Mail.dat does not handle.

The development of Mail.dat and Mail.XML is coordinated across DTAC so that any redundancy will not cause adverse effects.