How to Acquire the Windows 95 Exchange Inbox Update (Exupdusa.exe)

The Microsoft Exchange Inbox Update for Windows 95 (Exupdusa.exe) should be considered an update to the default Windows operating system's messaging subsystem. The Exchange Inbox Update installs a complete MAPI 1.0 subsystem and client with no other dependencies, like the Exchange 4.0 client. This allows the full MAPI subsystem to be installed without having a previous Exchange client installed on the computer.

This update is needed in order to allow certain MAPI related functions and up-to-date controls to function properly.

The following file is available for download from the Microsoft Download Center:
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file. To install the Exchange Inbox Update, double-click the file Exupdusa.exe.

NOTE: If the Exchange 5.0 client or any version of Outlook has been installed on the target computer after the installation of Windows 95, the Exchange Inbox Update should not be installed because the MAPI subsystem that it installs is dated earlier than the version that is installed by these other applications.