PST (Personal Storage Table) may get corrupt due to several reasons that are divided into two categories: hardware causes and software causes. Here, we'll cover both of them separately:
Viruses and other malicious software are capable of damaging Outlook PST files resulting in inaccessibility. A compromise with security can take users into complications, therefore, it is necessary to install adequate security software.
Every software subjects to technical issues that result in discrepancies; same applies to MS Outlook. The deficiencies and discrepancies in a program usually cannot be resolved by fixes. For example, in Outlook 97 to Outlook 2002, only 2 GB space was allocated for PST files. But, the rapid increase in data necessitated more space. In these programs, when PST file reaches or exceeds 2 GB, it is much likely to get corrupt. This is the one case. Secondly, sometimes, Microsoft Outlook throws an unexpected error saying "Microsoft Outlook has encountered a problem and needs to close. We are sorry for the inconvenience." The error terminates the program abnormally, which is again susceptible to corrupt the PST file.
Flaws in File System Recovery -
If in case of broken file system, user attempts to recover a PST, it is more likely to corrupt the file. Because of the damage in file system, some parts of original PST file are overwritten by useless data or are lost permanently.
Accidental Shutdown -
The procedural aspect of quitting the Outlook states saving all changes made to the PST file and clicking 'Close/Exit' menu item. However, the abnormal shutdown while accessing PST file leads to corruption. Accidental shutdown may be caused if power failure occurs or if user terminates Outlook when it is performing some other task, or if the computer is turned off unexpectedly.
Issues in Data Storage Device -
Problems with storage device may also lead to PST file corruption. For instance, if hard disk contains bad sectors and PST file is placed on these sectors, user may be provided with the incorrect or erroneous data.
Power Failure -
A sudden disconnection from power while user is accessing the PST file may leave the file in corrupt condition.
Faulty Devices on Network -
If a PST file is placed on a network server and user wants to access it, the process requires a remote access. The remote connection establishment uses cables, interface cards, hubs, routers etc.; problems in such devices may cause corruption in PST file.
To deal with PST file corruption, Microsoft has provided a utility named Inbox Repair Tool (Scanpst.exe). However, in severe damages, the tool fails to accomplish the task. To handle such cases, it is recommended to go for commercial software that offer successful PST file recovery. See reference :