How do I convert OST to PST after Exchange server crash?

When an Exchange Server crashes, users often lose access to their mailbox because the OST file is tightly linked to the Exchange profile. Since Outlook needs a live Exchange connection to export data manually, the normal export option usually doesn’t work. In this situation, the practical way to convert OST to PST is by using a standalone OST conversion tool.

After an Exchange crash, your OST file becomes orphaned (disconnected from the server). You cannot open it directly in Outlook. A dedicated utility like SysInfo OST to PST Converter can open the orphaned OST file without requiring a live Exchange server or Outlook configuration. The software scans the OST file, shows a preview of emails, contacts, calendars, tasks, and attachments, and then allows you to save everything into PST format safely.

Here’s how the process generally works:

1. Install and launch the OST to PST conversion tool.

2. Add the orphaned OST file from your system.

3. Preview mailbox data to confirm everything is accessible.

4. Select PST as the output format.

5. Choose a save location and start the conversion.

The tool maintains folder hierarchy, preserves attachments, and keeps metadata like To, From, Subject, and Date intact. If the mailbox is large, you can even split the resulting PST file to avoid corruption.