The easiest and safest method is to use a PST viewer that supports oversized PST files. Tools like SysInfo PST Viewer are designed to open large PST archives without Outlook and without imposing size restrictions. The software scans the PST file and displays mailbox data--emails, folders, contacts, calendars, and attachments--in a structured, read-only format.

Since the viewer does not depend on Outlook services, it avoids common issues such as freezing, crashes, or long loading times. You can browse folders, open emails, preview attachments, and search within the mailbox even when the PST size exceeds 50GB. The original data remains unchanged, which is important when working with archived or sensitive email data.