To view an OST file without Outlook, the easiest method is to use a tool like the SysInfo OST File Viewer. This software allows you to open and read the contents of an OST file without needing Microsoft Outlook or an Exchange Server. It's perfect for users who don't have Outlook installed or are facing issues opening their OST files with Outlook. Simply download and launch the SysInfo OST File Viewer, select the OST file you want to open, and the tool will display all the emails, contacts, calendars, tasks, and attachments stored in the file.
Read more: https://www.sysinfotools.com/recovery/ost-file-viewer.php