How to Fix OST File Synchronization Error?

Last Updated on January 5, 2021 by Henry Bray

The OST file as the root of your Outlook helps store and synchronize all data with the Exchange database. If there is no way to connect to the Exchange server, the OST file can be used offline. The OST file syncs automatically, so all your offline tasks will update once they are properly connected to the Exchange server.

However, it has been seen many times that when you open your MS Outlook or try to sync with your Exchange mailbox, you are prevented from doing so and hence you face various OST sync error messages. , Which appear in the sync log in the Deleted Items folder. Such synchronization issues occur when one or more corrupt or damaged email messages are found in the OST folder, which cannot be fixed during the synchronization process. Here in this blog we will study all the common synchronization issues of OST and find out the solutions to fix this OST file synchronization error.

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Why Exchange OST File Synchronization Error Occurs?

However not very often, but when you connect OST to Exchange mailbox, you may face many synchronization errors. Outlook 2003, 2007, 2010, 2013, 2016 and 2019 have different reasons for preventing synchronization with Exchange.

  • The network connection may be the main cause of the synchronization issue.
  • MS Exchange Server also fails more frequently, due to which Outlook cannot be synchronized.
  • Problems on the local computer are another common problem when Outlook malfunctions.
  • Sudden system shutdown, over-sized OST files, and virus attack are some of the most common reasons

How to Fix OST Synchronization Issue?

The OST of the Outlook email application is only synchronized with the Exchange Server mailbox when there is a connection to Exchange. The synchronized speed varies depending on the data size and Outlook version. Here we have explained different steps to solve out the OST synchronization issues, such as verifying user profile, cached exchange mode etc. you can follow the mentioned steps to get rid of this issues.

Step 1 – Verify Synchronization of OST files

You can follow these steps to check synchronization of Offline Storage files with proper attention –

  • Right Click on the folder you want to check and click “Properties”
  • Switch to “Synchronization” tab. If you don’t see the Sync tab, you haven’t set up your profile to use offline folders.
  • Select “Statistics” of this folder and check these attributes –
    • Server folder contains – Items
    • Last synchronized on – Date
    • Offline folder contains – items

If you did not experience any problems with OST synchronization, then the attribute value of the folder of Server as well as offline folder contents are the same. But, if you cannot find this values same, then there must be a conflict synchronizing both databases. In that case, you have to follow these processes to verify profile settings.

In Outlook 2010

  • Go to “File” menu and click “Account Settings”.
  • Now, choose “Account Settings” from the list.
  • Click “Data Files” tab and set “mailbox account name” as default.
  • Click Email tab, click “Mailbox – account name” and then “change”.
  • Make sure that “Use Cached Exchange Mode” is selected, and click “OK”.
  • In the “Account Settings”, click “Close”.
  • Quit “Outlook “and reopen it again

In Outlook 2007

  • Click on “Tools” then “Account Settings”
  • Click “Data File” and set “Mailbox account name as default”
  • In Email tab, go to “Mailbox – account name” and Settings.
  • Check the option “Use cached Exchange Mode” and click OK.

In Outlook 2003

  • In the Tools menu, click “Email Account”.
  • In in the Email section, make sure that “View or change existing email accounts” is selected, and click “Next”.
  • In the “Deliver new email to the following location” list, select “Mailbox – Account name”.
  • Click “Microsoft Exchange Server” object, and click “Change”.
  • Select “Use Cached Exchange Mode”, and click “Next”.
  • Click the “Finish” button.
  • Close the Outlook and restart Outlook again

Step 2 – OST File Synchronization

Now you can easily perform these two important methods to synchronize your Offline folder – Manual and Automatic method to fix OST file synchronization issues accurately.

For Manual Synchronization

This process will help you to synchronize offline folder for Outlook 2019, 2016, 2013, 2010.

  • Go to “Folder List” pane, choose Folder which you want to synchronize.
  • Go to “Tools” menu, click “Send/Receive”, then Microsoft Exchange Server, if you have specific folder
  • In Tools menu, go to “Send/Receive All” for all folders

As soon as the synchronization process starts, you will see a synchronization status message on your computer screen. If there are too many items found in your mailbox, and your offline folders have not been synchronized for some time, then in this case the synchronization process can take longer than 30-40 minutes.

For Automatic Synchronization

You can use this method to synchronize OST file with Exchange Server at any time you go online.

  • Choose “Tools” and “Options”
  • In Mail Setup, select “Send Immediately when connected”
  • In Send/Receive, select “Send/Receive groups” and check “Perform automatic send/receive when exiting”.
  • Then click “close”.

Step 3 – Create New OST File and Synchronize

If you are not able to fix the synchronization issue even after using the above methods and you are fail to synchronize it; then it may be happen that your OST file is corrupt or damaged. In that case, you have to recreate and re-synchronize the OST file.

How to Rebuild New OST?

  • Close Outlook email application.
  • Go to C:\Users\administrator\AppData\Local\Microsoft Outlook
  • Find the OST file and rename the old file with different extension. (For example, replace .OST with .OLD extension).
  • After renaming the file, a new file will be created
  • In Outlook, go to “Tools” and “Send/Receive”

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If you have an oversized OST file and you cannot access it, in this situation you can use the OST Splitter tool, which can split the file into smaller parts. If you still can’t solve the OST synchronization issue, you can try the scanost.exe or scanpst.exe tool developed by Microsoft. These are the default repair tools created by Microsoft to fix OST and PST files related issues. But if these tools also do not work, in this case, you can take the help of Regain OST to PST Converter tool that can efficiently solve all the problems related to OST files. It import and access the OST file through Outlook.

Regain OST to PST Converter tool is very reliable and professional as it can easily repair OST files that are severely corrupt or damaged which cannot be fixed by default repair tools. If the above methods are not longer helpful, use this tool to resolve data file problems and recover them with few easy steps.

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