I have an old PST file from a previous computer that I need to inspect, but the original Outlook installation and profile are no longer available. The PST contains historical business correspondence, and I would like to determine whether the required emails and attachments are still accessible before deciding what to do with the archive.

I know PST files are commonly used by Outlook for storing mailbox data, but I am not sure whether an orphaned PST can be safely opened without configuring the original Outlook account again. Recreating the old mailbox is not practical in my situation because the account is no longer active.

Would a standalone PST file viewer be appropriate for this type of situation? I mainly need to browse the mailbox structure and check the contents without modifying the source file.

The archive is fairly large, so being able to search through messages would also be important. I would like to locate emails based on sender, recipient, subject, and date rather than opening every folder manually. If attachments can also be identified during the search, that would be helpful for finding older project documents.

I am also concerned about password-protected or partially inaccessible PST files. Before attempting any repair operation, I would prefer to understand whether the existing data can be previewed safely.

While researching this, I came across SysInfo PST Viewer. Its product information says it can open healthy, orphaned, password-protected, and oversized PST files and preview mailbox items without requiring Outlook. It also provides search and filtering options for locating specific messages. 

For anyone who has handled an old Outlook archive after the original account was retired, what method did you use to inspect the PST? I am particularly interested in approaches that leave the original file untouched while allowing the mailbox contents to be reviewed.