Corruption problem occur in outlook when your pst file gets effected by virus or software problem occur. all your pst file become inaccessible after corruption problem. If you want to repair them than use pst repair tool.
The PST repair tool is a very powerful tool for fixing the damaged PST file. The user of any Outlook versions including Outlook 2003, 2007 and 2010 can easily use this tool to repair the corrupted PST file.