Outlook OST files store cached data but cannot be shared easily across platforms. To analyze emails or manage contacts outside Outlook, convert OST to CSV is the ideal option. The built-in Outlook export feature only works if your OST is active, which isn’t the case for orphaned files. Here, the OST Converter Tool is a reliable solution. It processes large OST files quickly, exports to CSV or other formats, and ensures formatting, attachments, and folder structures remain preserved.