OST PST Viewer: Open & View Outlook Mailbox Files

Key Features

• A free tool to search in, open and view OST PST data files without Microsoft Outlook.
• Open PST, OST and other Outlook file formats.
• The Enterprise edition unlocks all OST PST Viewer features.
• Change read/unread or follow up status of emails.
• Use advanced search to find exactly what you are looking for in your pst files.
• Save everything you need to your local drive or in other locations.

Technical Specifications

• **Publisher:** Ostpstviewer.com
• **License:** Freeware
• **Operating System:** Windows 7, Windows 8, Windows 10, Windows 11
• **Last Updated:** October 15, 2025
• **Category:** Business / Finance Tools