When you use Outlook Inbox Repair Tool (Scanpst.exe) to repair a damaged or corrupted Outlook personal folders(PST) file, the tool can find the errors in the PST file, but can only recover a small portion of the data, with all the remaining data lost in the fixed PST file.
The capability of scanpst is very limited. When the corruption or damage of the PST file is too severe, then scanpst will only be able to recover a small portion of the data.
You should use professional tool DataNumen Outlook Repair to repair the corrupt PST file. With sophisticated programming and algorithm methodology, DataNumen Outlook Repair will always recover most of the recoverable data form the corrupt PST file, much more than those recovered by scanpst, so it is the best Outlook recovery tool in the market.