Introduction
In this blog, we will see some reasons behind the Outlook OST Synchronization Error and how it can be fixed.
![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.
![Outlook OST Synchronization Error And How It Can Be Fixed?]()
Let’s look at a few common reasons behind ‘Outlook OST Synchronization Error’, and their solutions.
Network connectivity issues
Outlook synchronizes the 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.
Synchronization is interrupted
You may get the ‘Error 8004011D-526-80040115-0’ when the synchronization process of the 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.
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
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 files. Moreover, the ‘Inbox Repair Tool’ cannot fix oversized OST files (exceeding 2 GB).
Using a third-party tool
The best alternative to the scanpst.exe utility is a software-based solution that can help repair and restore corrupt/inaccessible OST files.
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 the Exchange server mailbox. However, synchronization at times can go wrong, resulting in ‘Outlook OST Synchronization error 8004011D-526-80040115-0’.
Also Read - Why is Outlook not showing all Emails?