Reasons behind 'Outlook OST Synchronization Error’ and how it can be fixed?

Reasons behind Outlook OST Synchronization Error and how it can be fixed?

In this article, we will see some 'Reasons behind Outlook OST Synchronization Error and how it can be fixed?'


When your Outlook application is unable to synchronize OST file with Exchange mailbox, you may encounter an error message like:
Outlook OST Synchronization error 8004011D-526-80040115-0’

As a result of this error, you won’t be able to send or receive emails.


Let’s look at a few common reasons behind ‘Outlook OST Synchronization Error’, and their solutions:

     1.     Network connectivity issues

Outlook synchronizes OST file with the Exchange mailbox, when the connection to the server is available. However, limited or unreliable connectivity of Outlook with Exchange Server can result in synchronization error. Such a situation even makes the OST files inaccessible.

Solution: Check all your network connections for proper functioning, and then try resynchronizing the Offline folders

     2.     Synchronization is interrupted  

You may get the ‘Error 8004011D-526-80040115-0’ when the synchronization process of Outlook and Exchange server is interrupted due to:
  • Sudden power failure
  • Network problem

Solution: Wait till the Exchange server comes back online and synchronize your OST file again.

     3.     OST file corruption

The ‘OST Synchronization Error’ is also generated when the OST file you are trying to synchronize with the Exchange server mailbox is found to be corrupt.

Note: You can try restoring the OST file data from backup. This method, however, won’t work in case you haven’t created a backup prior to the synchronization process. If so, you’ll need to repair the corrupt OST file.

Solution: OST file can be repaired by using the following methods:

Method 1 – Leveraging the Microsoft inbuilt Utility
Microsoft recommends using its built-in utility, the Inbox Repair Tool (also called scanpst.exe), to diagnose and repair errors in Outlook data files. The steps for using the Inbox Repair Tool to repair Outlook data files.

NOTE: While this method is easy to understand and implement, it has some limitations, the most important being its inability to fix severely damaged or corrupted OST file. Moreover, the ‘Inbox Repair Tool’ cannot fix oversized OST files (exceeding 2 GB).

Method 2 – Using a ‘Converter for OST’ Software
The best alternative to scanpst.exe utility is a software-based solution that can help repair and restore corrupt/inaccessible OST files.

Use Stellar Converter for OST, as the software reduces the data loss risk by converting all the OST file components to an Outlook compatible (PST) format.

A few other reasons that makesStellar Converter for OSTsoftware worth-trying are:
  • Converts inaccessible or encrypted OST files, into PST files
  • Allows converting OST files into PST files without worrying about file-size limitation
  • The extracted data (comprising emails, calendars, and deleted items) in PST file is available as “Preview” for user verification
  • The software makes it easy to import and sync PST file into Outlook
  • The software provides free OST to PST conversion for first 20 emails per folder and much more.

A Few other recommendations

  • Check whether the offline folders are synchronized correctly or not
  • Try disabling the anti-virus software (if any) 

Summing Up!
As you can never predict when you may encounter server downtime, network or file corruption issues, it becomes imperative that you have synchronized your Offline data file (.ost file) with Exchange server mailbox. However, synchronization at times can go wrong, resulting in ‘Outlook OST Synchronization error 8004011D-526-80040115-0’.
Though plenty of solutions are available to fix the error, you may try using ‘Converter for OST’ software. Such a software not only restores the corrupted/encrypted/large-sized OST files, but also converts them into an Outlook compatible PST format.


Post a Comment


  1. Thanks for sharing that informative stuff !

  2. There can be multiple formats for the OST file corruption, but to fix all errors safely and quickly simply use eSoftTools OST to PST Converter Tool. This tool help to auto detect location of corrupted OST file and recover data of file with including all folders. By using this tool you can easily convert OST file into multiple formats like Office 365, MBOX, CSV, EML, MSG, vCard, HTML, PST Outlook.
    Get more info:- Convert OST to PST

    1. Thanks JackBryan, for your time and thanks for the suggestion !!

  3. Thank you for such a nice post. It is very informative but, before executing these methods it will be good if you take backup because sometimes it doesn’t work properly. The safest answer to this problem is third-party OST to PST converter. These tools easily repair your damaged OST file and recover all data quickly. After that user can easily export recovered data into PST file format. Here I want to suggest Syscurve OST Converter Tool. Because it is one of the most advanced software that gives you a secure and reliable conversion. It also allows users to export OST data to PST, MSG, EML and MBOX file format.

    1. Thanks Deepak Singh Bisht, for your time and thanks for the suggestion !!
      Please keep visiting..

  4. Informative stuff !!
    Thanks for sharing!!

  5. I am happy share SysInspire OST to PST Converter software that resolve all error related Exchange OST errors. Above post is really helpful for all. You can export OST items to PST, EML, MSG, Office 365 and many more

    Get the complete details -


  6. Try OST to PST Recovery software and instantly repair corrupt OST files and convert Outlook PST format. This software also convert EML, MSG and HTML PDF format. Read more information and free download click here :

  7. If you are looking for a reasons behind 'Outlook OST Synchronization Error’ and how it can be fixed, then you can try the most prominent Cigati OST Converter Tool.

  8. Now users can repair and restore corrupted or erased OST files by taking help of OST to PST Converter Software that efficiently extracts all the mailbox data like emails, attachments, journals, and notes. This software takes the least time to recover erased OST mailbox items and maintains the folder hierarchy. Further excellent features of Offline OST to PST Converter Software. This Application Supports MS Outlook 2003, 2007, 2010, 2013, 2016, 2019. It also supports all Mac OS & Windows versions. Go ahead and download the free trial version software.

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