There are many circumstances where Outlook OST file data is beyond access and throws errors. Such symptoms are not shown at primary corruption but as the level of corruption increases it starts showing counteract reaction to such damages in OST file. The very primary symptom is error message display which is prompted on OST data access. This blog will discuss about such errors, its causes and a mechanism to recover .ost file to .pst file. Many users might have experienced that while opening MS Outlook application, too much of time is consumed or once it is open application is very slow to execute. Sending or receiving emails becomes slow and lethargic. Moreover, when some emails or any particular folder is supposed to be accessed, errors are prompted. All these things indicate that the storage database of Outlook application has been disfigured and thus Outlook application is unable to display the data in an organized manner. Let us see what leads to these damages and what can be its probable remedies? Oversize OST File Can Be Threatening MS Outlook 2002 and below versions have a size limit of Outlook data file as 2 GB. When this file limit is reached, OST file starts troubling you. At this stage it is better to recover .ost file to .pst so that these issues are managed. It has been observed that following issues start occurring once the size limit is approached; Unable to open or load OST file at all. New data or emails cannot be added to file. Synchronization with Exchange server mailbox is not done. Synchronization takes place but errors are thrown. Particular email folder is unable to get accessed. Errors Occurred On Damaged File Access When you try to open MS Outlook with damaged OST file following error message is displayed; Errors have been detected in the file xxxx.ost. Quit all mail-enabled applications, and then use the Inbox Repair Tool. While adding new emails through synchronization, Outlook application stops accepting new data and error message is thrown; Task 'Microsoft Exchange Server' reported error (0x00040820):'Errors in background synchronization. How to Resolve Such OST File Errors? The immediate action taken by you must be close this program and run inbuilt repair utility on the OST file which is showing issues. You can archive the exiting data of OST file to PST file but since this file is corrupted the archiving procedure will not be done properly. In order to bring out the recovery process and recover .ost file to .pst file you will have to yield help from a third party solution like OST to PST Converter which is profound solution for recovery of data inside OST file to another PST file which can be accessed without any errors.