The Inbox Repair tool, commonly known as scanpst.exe, is a built-in repair tool comes with MS Outlook client. By using scanpst.exe utility, we can scan corrupt PST files for errors and fix them. But scanpst.exe may fail or not work in case of severe corruption. It can only fix header corruption issues. In such situation, we must try a professional recovery solution. There are many software vendors in the market which provide PST repair or recovery tools. Most of them are available with demo/trial version for free evaluation. So before we can purchase any such tool, we should download free demo/trial version. Why? Demo/trial version can help us check what could be recovered from the corrupt PST files before actually paying for the software. And if we're satisfied, then only we should purchase the software.

I hope the shared information would be helpful here.