Summary: Exchange OST files are the medium to continue functionality on local machines while Exchange Cached Mode is turned ON. Sometimes, these files turn corrupt and this further affects mailbox functionality. The blog lists all the reasons that are responsible for Exchange OST corruption including Hardware-related as well as software specific.
OST files are the replica of user mailboxes stored on Exchange Server that helps continue functionality even when Exchange Cached mode is enabled. Sometimes user requires working offline, either by choice or due to connection issues. In such situations, OST allows working in the offline mode as the copy of the mailbox is available locally that provides instant access to data.
When the connection rebuilds, the OST file automatically syncs with Exchange Server mailbox to update data. The overall functionality may appear smooth, but this is not the case. Similar to other files and apps, the OST files also turn corrupt. In majority of cases, OST files are the victim of unreliable internet connectivity.
During OST synchronization, if the process is interrupted or suspends due to weak internet connection, the OST file turns corrupt. This is when the situation becomes serious as it affects the functionality to a great extent. Apart from this, there are other OST file corruption reasons as well that makes Outlook data files inaccessible. All such reasons can be categorized into two major sections – Hardware Related and Software Related.
Hardware related issues are the problems that are created due to malfunctioning, failure, or inappropriate configuration of any of the external components of the computer. These components include hard drive, internal or external power unit, network connectors, modem, etc. There are a number of reasons that affect the functionality of hardware devices.
• Affected Storage Device: If you find the storage device working slower than usual, there can be a combination of reasons that are responsible behind this issue such as faulty hardware or bugs. The unexpected performance of the storage device can be due to malfunctioning of any component or due to virus infection.
• Interruption due to Network Connectors: Issues cropping up due to inappropriate functionality of the network cards, cables, routers, and other similar devices affect the functionality of the OST files as it fails to synchronize properly. It is recommended to check the network connections and devices to ensure that they are working as per standard.
• Bad Sectors on the Hard Drive: This is one of the major reasons for OST file corruption. It affects the functionality parameters of the hard drive and its performance degrades to a considerable extent. It even causes corruption in the files stored on it. OST corruption could be the result of the existence of numerous bad sectors on the device.
• Sudden Power Loss/Surges: Unexpected power failure sometimes result in OST file corruption if the instance occurs when user is actually working with the file. In addition to sudden loss of electricity, there are times when the supply is comparatively higher and the machine gets affected with excess power supply.
Software related problems are the errors and issues that occur due to logical inconsistencies and incompatibilities. These errors are often caused by virus infections, bugs transmission, downloading applications from unreliable resources, application failure, and other similar reasons. Some of these common errors are mentioned in this section.
• Stipulated Storage Limit: As a matter of fact, every individual file being used for data storage is liable to specific storage capacities. When OST file is about to reach this stipulated limit, it turns corrupt or even becomes inaccessible. Thus, you need to repair the Outlook OST file in order to gain access to the incorporated data. It is better to compact and split OST file on a regular basis in order to keep it organized.
• Abnormal Termination of Outlook: Once you are done with all MS Outlook tasks and emailing functions, remember to exit all open windows and dialog box. Do not close a process while it is in operation otherwise, the associated files may turn corrupt and the OST will become inaccessible. In severe cases, the application itself may freeze or shut down abruptly.
• Incompatible Outlook Add-in: Sometimes, the problem lies in the add-ins installed with Outlook. To resolve this issue, you will need to disable COM add-ins from MS Outlook Options menu by selecting Addins option and then clicking on Manage. Disabling addins on ‘one-on-one’ basis helps detect the actual add-in that is creating issue.
• Deficiency in Outlook Program: In several cases, it is the application itself that is creating frequent issues with the OST or even PST files. In such situations, it is really hard to detect the actual cause, but several workarounds may help detecting the original cause of error and repair Outlook OST file. Such problems can only be rectified from developer’s end.
More details about the Errors due to OST file corruption:
Recover OST Data from Physical & Logical Corruption
Whatever be the cause, whether physical breakdown or logical inconsistencies, the consequences will be definite; under all situations, data incorporated under OST files is targeted. Even though, the errors that occurs due to logical inconsistencies are quite possible to resolve, it is difficult to retrieve data from a severely damaged OST file. In this case, OST to PST Converterby Stellar Data Recovery helps to retrieve data from corrupt OST file to PST file format. Later you can import PST file into MS Outlook to access OST file data.
Stellar Converter for OST Video Tutorial
Moreover, OST Integrity Checker tool also known as ScanOST.exe is known to resolve minimum corruption issues with the OST files; but the built-in tool is no more available with MS Outlook 2010 and onward releases. Microsoft now recommends deleting the OST file and then re-downloading it from the Exchange Server.
This method helps gain access to data stored in the OST, however, the changes recently made to the file will be lost. The data that is deleted or edited in the OST file since last synchronization will not be updated on the Exchange Server mailbox. However, the entire data that has been deleted due to corruption or deletion from the OST file can be regained by employing Stellar Converter for OST software.
Eric Simson is an Email Platform Consultant and is associated with Stellar Data Recovery from last 6 years. He writes about the latest technology tips and provides custom solutions related to MS Outlook, MS Exchange Server, Office 365, and many other Email Clients & Servers.