The outlook is one of the most used applications provided by Microsoft. Sometimes while using the same, you may face synchronization problems with Outlook and Outlook Web App. The sync error can happen for a number of reasons. In the guide provided here, you will find the reason for synchronization problem and the ways to fix the same with the help of Outlook Support team.

Symptoms of Outlook synchronization error

You will face the following symptoms when synchronization issues occur in Microsoft Outlook or in Microsoft Outlook Web App, you may experience the following symptoms.

  1. You will see differences between the messages received in Microsoft Outlook when you will compare it to Microsoft Outlook Web App.
  2. There is an issue with Outlook but the issue doesn’t arise when the cached mode is disabled.
  3. You will receive an error message sometimes when you synchronize the Offline Folder file (.ost) in Outlook with the mailbox on a server that is making the Microsoft Exchange Server run. The error message you will see will be something like this-

‘Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. The file c:\Users\<username>\AppData\Local\Microsoft\Outlook\<> is not an Outlook data file (ost).’

  1. You will notice that some items such as emails, appointments, contacts, tasks, journal entries, notes, and documents are not there in your .ost file or are missing from your mailbox after you synchronize the .ost file and the mailbox.

Whenever you see these symptoms occurring, or you have other problems related to synchronization, the problem might be due to a corrupted .ost file. You can immediately contact the Outlook Help and support team.

Solutions to fix synchronization error 

Outlook 2003 and Outlook 2007

You can use the OST Integrity Check Tool (Scanost.exe) to check your .ost file for inconsistencies.

Outlook 2010 version and later 

The OST Integrity Check Tool (scanost.exe) is not there in Outlook 2010 and later versions. This tool was available in earlier versions to fix errors in Outlook data files (.ost). If there is an issue with a specific folder, you can re-sync the folder in Outlook using these steps:

  • Right-click on the folder and click on the ‘Properties’ option.
  • Next, select ‘Clear Offline Items’, and then press ‘Ok’.
  • Click on the Send/Receive tab in the Outlook 2010 ribbon and then click ‘Update Folder’.

If this didn’t help, you can rebuild the .ost file by deleting the .ost file first and then Outlook will download the information again from the Exchange Server.

In case, you have local data that is not present on the server you can follow these steps:

  1. Export the data to an Outlook Data File (.pst), and after that delete the .ost file.
  2. Let the server data download, and then import the .pst file data using the option ‘Do not import duplicates’. You will find this option by clicking on the File tab and then click the Open option.

Outlook Customer Service can also be contacted if you have issues left to be resolved. The technicians are really helpful and have good knowledge to fix Outlook problems. 

Read More Blogs: