Outlook’s ability to connect to the mail server may be blocked by firewalls or antivirus software. After you’re satisfied, turn off your firewall or antivirus program for a while. If it does, understanding you might need to include Outlook exceptions in the settings of your security program. The sync will fail if the groups you selected to load users from no longer exist in Azure AD.

Methods to fix Microsoft Outlook syncing error

• We're in the process of migrating from On-Premise Exchange to O365.
• We have resources to help you identify potential issues and fix them.
• After you’re satisfied, turn off your firewall or antivirus program for a while.
• After the files get repaired, restart the Outlook program to ensure that the Outlook syncing issues are resolved or not.
• Similarly you should review the Users Deactivated sheet on the sync summary spreadsheet attachment as you can also delete these users to bring your total down.
• Here, we will discuss the five manual methods to fix sync issues in Outlook or OWA.

This blog talks about the causes behind Outlook synchronization errors and a few solutions to fix Outlook sync issues. We have shared five manual methods in this blog to resolve the Outlook syncing errors. Apart from this, we also discuss the Shoviv OST to PST Converter Tool, a professional way to repair, recover, and convert Outlook data files. This solution will be beneficial for users who are facing Outlook syncing issues because of corrupted PST or OST files.

Common Causes of Sync Issues in Outlook

Before finding solutions, we suggest that users check their internet connection. Sometimes, Outlook sync issues can arise because of poor internet connection. If you are still facing this issue, kindly follow the solutions below to fix the sync issues in Outlook. There are various methods to resolve the Outlook sync issues, including manual and third-party solutions. Now, let us start with the manual processes to fix Outlook syncing errors.

[Answered] Secured OST to PST Converter for OST to PST Conversion

So, follow the below steps to reset Microsoft Outlook settings. The sync does not delete users but rather sets them to inactive. The idea is to provide a recycle bin of users who you can delete when you no longer need them. You can view your inactive users on repair corrupted OST in Outlook the Users page and delete them as you see fit.

What should I do if my sync failed due to authentication issues?

If users are facing syncing issues in Outlook due to corrupt Outlook data files, they must choose a professional tool, like Shoviv OST to PST Converter Tool. This software allows users to process numerous OST files at once without any size limitations. Moreover, it maintains the folder hierarchy and metaproperties of the data when processing Outlook data files. This tool also helps users fix Outlook syncing issues by repairing OST or PST files and syncing the data smoothly. Here, we will discuss the five manual methods to connection status shows disconnected fix sync issues in Outlook or OWA.





Typically this is because the selected groups have been deleted from Azure AD since the M365 sync was configured on your account. After viewing, see fixing problems with directory synchronization for Microsoft 365 to correct any identified issues. There can be several reasons for the Outlook synchronization error. Before we know the solutions, we will understand a few common causes of the Outlook sync problem. To get the sync working you will either need to delete users or have the user limit on your account increased. If you don't wish an inactive user to be made active by the M365 sync, you can add the user's email address to the sync forbid list.

What privileges do I need to authorise the M365 sync?

Outlook sync issues can be because of corrupted Outlook OST or PST files. Therefore, now we will know the steps to repair the Outlook data file. To resolve these issues you should run the steps in this article and check whether the groups in your sync's filtering preference contain users in Azure AD. The Sync Summary email can give further information about this. The Users Loaded count will be 0 if all users fail to meet the system's requirements for user records. The Users Processed count will be 0 is there are no users in the synced dataset after filtering.



The sync will fail if it can't find any users that comply with your filtering preferences or the system's requirements for user records. The system requires that users have a first name, last name and a valid email address that conforms with your domain lock if enabled. The most common reason for missing users is that you've run a Test Sync, instead of a Manual Sync. If that doesn't resolve your missing users issue, please follow our guide to troubleshooting missing users below. With directory synchronization, you can continue to manage users and groups on-premises and synchronize additions, deletions, and changes to the cloud.