Convert Orphaned OST files

An orphaned OST file is an Outlook offline data file that has lost its connection to the original Exchange Server or Microsoft 365 account. This happens when you leave a company (account deleted), switch computers without migrating properly, have a corrupted Outlook profile, or when your M365 subscription ends. The file contains all your cached emails, contacts and calendars but Outlook cannot open it because it cannot verify against the server.

Yes, absolutely! Univik OST Converter works completely independently of Microsoft Outlook. It reads the OST file structure directly using proprietary parsing algorithms. No Outlook installation, no Exchange connection, no active account needed. This is exactly what makes it suitable for orphaned file recovery.

Yes, 100%. The complete folder hierarchy is maintained during conversion. All folders, Inbox, Sent Items, Drafts, Deleted Items, Calendar, Contacts, Tasks, Notes and any custom folders you created, are preserved exactly as they appeared in the original OST file, including nested subfolders.

In many cases, yes! Our deep scan feature searches the OST file's "Recoverable Items" container where soft-deleted emails are stored. If the items haven't been permanently purged (which typically happens after 14-30 days depending on Exchange settings), they can be recovered. The tool will show recovered items in a separate folder.

OST (Offline Storage Table) is a local cache that synchronizes with Exchange/M365 servers, it's automatically created and tied to a specific profile. PST (Personal Storage Table) is an independent data file you create manually for backup or archival, it's portable and can be opened on any computer with Outlook. Converting OST transforms server-dependent data into a portable, independent format.

Univik OST Converter can handle OST files of any size, including large files up to 50GB or more. The software uses optimized memory management and streaming techniques to process massive mailboxes without crashing or requiring excessive RAM. For very large files, conversion may take longer but will complete successfully.

Your data is completely private and secure. Univik OST Converter is a desktop application that works 100% offline. All processing happens locally on your computer. No data is ever uploaded to any server, no internet connection is required for conversion and we have no access to your files. Your sensitive emails remain on your machine only.