How To Analyze Corrupt OST Data From Outlook Offline Mailbox

admin | November 14th, 2016 | MS Exchange & Outlook

When users work in online mode in Outlook with the mail server, sending and receiving of mails is just a click away. Mails are easily sent at the same moment you click on the send button. However, there are instances, when working online in Outlook is not as empirical as it seems. For example when you are at a location where network is unavailable like on a flight. Alternatively, you have access to internet connection, but do not want to use it right away. Once offline, the users lose access over the data stored on the server. This is when OST files come into existence.The OST files are righteously said as the replica of Exchange mailbox. When users are online any changes made to any of them (OST or mailbox) is automatically carried out in another.

Certain issues in the network or in the synchronization process may lead to corruption of OST files, which at times go unnoticed by the user. So the question is ‘How to analyze corrupt OST data from Outlook offline mailbox’? In this blog, we have put together some errors in OST files, which point in the direction that OST files have been corrupted. In addition, the method to resolve the error is discussed.

Analyzing Corruption In OST Files

At times Outlook users encounter various errors while they work with OST files. Also sometimes Outlook performance gets degraded, for example the mails take more time to open, Outlook itself takes consumes more time than required for starting. All the issues point in the direction that the OST files have undergone corruption. In order to help the users to identify that the encountered errors indicate corruption in OST file, we have listed some of the errors.

  • You can encounter this error when the OST file does not successfully synchronize with Exchange server. Users tend to think that this is the only reason, but this is not true. When this error occurs, get a slight hint that the OST file has been corrupted.
    Cannot open your default  email folders. The file xxxx.ost is not an offline folder
  • When Exchange server is not operational, you can get the following error. Make sure that you are not getting this error frequently, because this may lead to corruption of OST files. If this is happening frequently, then there is definitely issue with your OST file.
    Exchange is currently in recovery mode 
  • This error comes up due to synchronization problem between OST file and Exchange server. The major reason behind this error is the corruption of OST files. Since corrupted files cannot be synchronized, hence this error.
    Synchronization Error 8004011D-526-80040115-0

Analyze Corrupt Data from Outlook Offline Mailbox

When you get any of the above-mentioned errors, it straightaway means that your offline mailbox data in OST file has been corrupted. In such case, it is impossible to access the data in these files. Therefore, in order to analyze corrupt OST data from Outlook offline mailbox the first thing to be done is the repairing of OST files. This is because once the files are repaired then only it is possible to analyze data in the files. There are methods available to do so.

Method: 1

Repair your OST file with Scanost.exe tool. Scanost.exe is an inbuilt utility provided by Microsoft to enable the users to scan the OST files for errors. The utility scans the complete OST file and if errors are observed, eliminates the error and repair the corrupted data. Although this is an inbuilt utility, but it does not guarantee complete recovery of corrupted data of OST files. At times, it happens that it deletes the corrupted data and produces the healthy data.

Note: It is to be noted that Scanost.exe is no longer supported after MS Outlook 2010. Therefore, for scanning and repairing OST files another in-built utility Scanpst.exe can be deployed. It scans both PST and OST files and repairs them in case of corruption.

Method: 2

In case the OST corruption is too high, Scanost.exe will not be able to recover the data. Therefore, you can deploy third party tools like OST Wizard. It is the perfect solution for the query ‘How to analyze corrupt OST data from Outlook offline mailbox?’ It is an efficient tool, which makes the OST data accessible by recovering it and saving it in PST, EML, EMLX, MBOX, HTML, XPS, RTF, DOC, etc. file formats accordingly. The application is programmed in such a way that it supports all Windows as well as outlook editions. The software does not require Exchange connectivity with Outlook; it only needs OST files to perform the process.


For efficient analysis of corrupted data in OST files, it is advised to take help of third party tools as they recover the data even from highly corrupted OST files. The tool consumes less time and efforts as compared to manual method and ensures complete recovery of lost data.