OST Viewer: Open Outlook OST Files Without Outlook

Key Features

• OST Viewer is a specialized utility that allows users to open and view Microsoft Outlook OST files without having Outlook installed or connected to an Exchange server.
• It enables users to read emails, view contacts, calendar entries, and tasks stored in offline Outlook data files.
• This is particularly useful for recovering data from orphaned OST files left behind after an Exchange server crash or account deletion, allowing users to access their archived information without needing the original email profile.

Technical Specifications

• **Publisher:** Ostviewer.com
• **License:** Freeware
• **Operating System:** Windows 7, Windows 8, Windows 10, Windows 11
• **Last Updated:** October 15, 2025
• **Category:** Utilities / File Managers