SysTools OST Recovery: Complete Guide to Restoring Corrupted OST Files

How to Use SysTools OST Recovery to Repair Exchange OST Data

When an Outlook OST becomes inaccessible or corrupted, SysTools OST Recovery provides a straightforward way to repair the file and extract mailbox items (emails, contacts, calendars, tasks, notes, journals). The steps below assume a Windows PC and cover installing the tool, scanning an OST, previewing results, and exporting repaired data back to Outlook or to common file formats.

What you’ll need (assumptions)

• Windows PC with .NET Framework 4.5+
• The OST file you need to repair (single or multiple) accessible on the system
• Microsoft Outlook installed only if you plan to export to PST using the “Use Outlook” option
• If exporting to Office 365, an admin account with impersonation rights

1. Download and install

1. Download the SysTools OST Recovery installer from the vendor site.
2. Run the installer and follow the setup wizard (accept license, choose install folder).
3. Launch the application after installation.

2. Add the OST file(s)

1. Click Add File or Add Folder to select a single OST or bulk files.
2. Optionally use the software’s Auto-Locate feature to search drives for OST files.
3. Choose Quick Scan for minor corruption or Advance/Deep Scan for severe corruption.

3. Scan and preview recovered items

1. Start the scan. The tool will analyze and repair data structures inside the OST.
2. When scanning completes, browse the recovered mailbox tree in the left pane.
3. Use preview modes to inspect items (email body, attachments, contacts, calendar entries). Deleted items are typically highlighted (e.g., red).

4. Filter and confirm what to export

1. Use built-in filters (date range, folder selection, item types) to limit exported data.
2. Confirm that metadata (read/unread, timestamps, sender) appears preserved in previews.

5. Export repaired data

Choose one of these export options depending on your goal:

• Export to PST: Select PST and, if required, enable Use Outlook (Requires Outlook). Optionally split PST by size to avoid very large files.
• Export to Office 365: Choose Office 365 and enter admin credentials (impersonation required).
• Export to other formats: MSG, EML, HTML, PDF are available for single items or folders.

Export steps:

1. Click Export, choose format and destination folder.
2. Configure options: item filters, PST splitting, remove encryption (for S/MIME/OpenPGP — requires keys/passwords).
3. Start export and wait for completion. The tool shows progress and a final report.

6. Import repaired PST back to Outlook (if needed)

1. If you exported to PST, open Outlook.
2. Use File > Open & Export > Open Outlook Data File and select the exported PST, or use Import/Export to import items into an existing profile.

7. Verify results and cleanup

• Open several restored emails, contacts, and calendar items in Outlook to confirm integrity.
• Keep originals until you confirm complete recovery.
• Delete any temporary files created during scanning if not needed.

Troubleshooting tips

• If scan fails, retry using the Advance/Deep Scan option.
• For encrypted messages, provide the required decryption certificates/private keys.
• If exporting to Office 365 fails, ensure admin impersonation is configured and network connectivity to Office 365 is available.
• Use the trial version to verify recoverability (trial exports are limited to 25 items per folder).

When to use SysTools OST Recovery

• OST files corrupted by disk errors, sudden shutdowns, or application crashes.
• Need to extract mailbox data from orphaned OSTs when server/mailbox is deleted.
• Converting inaccessible OST to PST/EML/MSG/Office 365 for migration or archival.

Final notes

SysTools OST Recovery is a commercial recovery utility with a free demo that previews and exports a limited number of items per folder. For full exports, purchase the full license and follow prerequisites (Outlook for PST export via “Use Outlook” option, Office 365 admin impersonation for cloud export).