I have several Outlook PST files from an old email archive, but Microsoft Outlook is no longer installed on the system where I need to process them. I want to extract the emails and other mailbox data into more accessible formats, but I am not sure which conversion method would be safest for a large PST archive.

The PST files contain thousands of emails, attachments, contacts, and calendar entries. Some of the files are several GB in size, so manually opening and exporting individual folders is not practical. I also want to preserve the original folder structure because the mailbox contains many custom folders and subfolders that are important for organizing the historical correspondence.

While researching standalone PST conversion software, I came across SysInfo PST Converter. According to its documentation, the application can process PST and OST files without requiring Microsoft Outlook and supports batch conversion. It also provides a preview of mailbox folders and attachments before exporting the selected data. The tool supports formats such as MBOX, EML, MSG, PDF, CSV, JSON, DOCX, VCF, and ICS, along with migration to platforms such as Microsoft 365, Google Workspace, and IMAP accounts.

What I am mainly trying to determine is how reliable this approach is for a large archive. I would like to filter the mailbox before conversion instead of exporting everything. For example, if I only need emails from a particular date range or selected folders, can those items be processed without converting the complete PST?

Attachments are another concern. Some emails contain important documents and images, so I need the message content and attachment relationship to remain intact. I also noticed that the software provides options for handling attachments and maintaining the original folder hierarchy.

Has anyone used a standalone PST converter for a multi-GB Outlook archive without having Outlook installed? I would appreciate practical advice about validating the converted data, especially email counts, folder structure, attachments, timestamps, and metadata before deleting or moving the original PST files.