Introduction MFCMAPI (Microsoft Foundation Classes Messaging Application Programming Interface) is an essential, open-source tool for developers, system administrators, and Exchange troubleshooters. Often called the “MAPI Swiss Army knife,” it provides deep, low-level access to MAPI stores, such as Exchange mailboxes and Outlook data files (PST/OST). If you need to view, modify, or debug hidden folders, properties, or extended MAPI behaviors, MFCMAPI is indispensable.
