Cannot open your default email folders, the file xxxx.ost is not an offline folder file Error : Explained

Resolve Cannot open your default email folders, the file xxxx.ost is not an offline folder file Error

Learn how to resolve ‘cannot open your default email folders, the file xxxx.ost is not an offline folder file’ error, the reasons due to which this error message appears and the steps that can be taken to cure the affected OST file from above stated situation.

The OST files are the replica of local machine Outlook mailbox data on Exchange Server. The above mentioned error message makes OST files inaccessible and when the user tries to view that particular file, it denies access in Outlook.  So to cure the file in order to make it accessible, it is necessary to know about the reasons that are responsible for occurrence of OST file error.

Why this Error Message Appears in Outlook?

The factors that contribute towards the error are summed up below:

•  OST file corruption that restricts MS Outlook from accessing the file.
•   Interrupted synchronization process leads to occurrence of this error.
•   The Exchange mailbox to which the file is associated has been deleted accidently.
•   Network or connectivity issue persists within Exchange Server and Outlook.

The After Effects of Existing Error:

The error message when appeared in Outlook sometimes affects the overall functionality of entire email application and restricts the users from using it for send\ receive emails. It may leads to severe aftermaths such as:

•   Denies accessing data incorporated in the OST file and it may leads to information lapse.
• The file may affect the whole mailbox data and user could not be able to open its mailbox in Outlook.

Measures to Cure OST File from Error:

Any sort of corruption in OST file can leads to inaccessibility of mailbox data and could affect overall functionality and communication process. So recovering them from corrupt mode is extremely important. The below mentioned measures can be practiced to cure the corrupt OST file and bringing it back to functional mode.

Method 1: Locate and Check File Information:

1.   Locate OST file that is dealing with ‘the file xxxx.ost is not an offline folder file’ error and try to explore the corruption reason(s).
2.   Ensure that the user profile information is correct in Outlook and Exchange Server as well.
3.  Ensure there is reliable internet connection persists between Outlook and Exchange Server.
4. Try to rename the corrupt OST file with a new name and then try to open it in MS Outlook (if Outlook is working).

Method 2: Diagnose Hardware and Software Issues:

To resolve the error issue, ensure there are no application or files conflictions and make sure that all the components of hardware are working appropriately. Ensure proper working of network components such as connectors, routers, data cards, etc. and there is no interruption exists.

If all of the above said methods do not work out to cure the corrupt OST file and making it accessible then try following the below mentioned procedure which is quite technical and must be followed out in an appropriate manner to avoid any loss of data.

Method 3: Delete and Recreate the Existing Profile:

The issue can be resolved by deleting the existing profile in MS Outlook and try to create a new profile with appropriate information. Follow the steps below:

Note: You must backup all mailbox data files prior to deleting the affected profile.

                1.   Click on “Start” button and further select and open “Control Panel”.

                2.    In “Control Panel” window, click on “Mail” to open it.

              3.    In “Mail Setup” window, click on “Show Profiles” option.

               4.    From the list of profiles click and select the profile that has to be removed.

               5.    Next click on “Remove” button to eliminate the selected profile.

Note: All profiles information is displayed in blank area under “The following profiles are set up on this computer” as mentioned in the figure.

                6.    Afterwards click on “Add” button to create and add new profile.

                  7.    Provide appropriate account information and click on “OK”.

                  8.    At last, launch Outlook profile and see if the problem disappears.

So by following the above stated steps carefully, you can get rid of ‘the file xxxx.ost is not an offline folder file’ error issue and can access data encapsulated in the OST file by bringing it back to accessible mode.