Announcements
01/08/2026
Earn a Free Professional Development Certification From the PCCAC
Release Notes
01/08/2026
July 2026 Release Overview

Note: For the latest technical specifications, please see the July 2026 Price Change Release Notes as they are published. Mail.dat and Mail.XML updates required for this release. 

Announcements
01/08/2026
INFORMATIONAL - USPS Mail Flow 101 Webinar Posted To PostalPro
Announcements
01/08/2026
INFORMATIONAL: 2026 Southern Area AIM Meeting - Orlando, Florida - SAVE THE DATE!
Announcements
01/08/2026
INFORMATIONAL: Federal Register: Manifest Mailing System Retiring
Presentations
01/08/2026
USPS Mail Flow 101 Webinar Recording
Announcements
01/08/2026
INFORMATIONAL - Postal Service Updates for January and February 2026 SDC Activations
Contact Lists
01/08/2026
CASS™ Certified Products Guide: Residential Delivery Indicator Cycle O - (Expires July 31, 2028)
Contact Lists
01/08/2026
RDI™ Cycle O: Certified Products Guide (D) - (Expires July 31, 2028)

This document outlines the CASS/MASS certified vendors list for RDI™ Cycle O.

Contact Lists
01/08/2026
CASS™ Certified Products Guide: M L O C R Mailers/Users Data File Cycle O - (Expires July 31, 2028)