The sync will fail if the total number of all users (active or inactive) on your account exceeds the user limit placed upon it if present. The Summary sheet on Outlook data file cannot be accessed the spreadsheet attachment of your sync summary includes an Updated User Count and User Limit. These figures will give you an impression of how far over the limit the account is.

Methods to fix Microsoft Outlook syncing error

• If you are still facing this issue, kindly follow the solutions below to fix the sync issues in Outlook.
• You can close the wizard at this point as you do not need to complete it for re-authentication to take effect.
• The other solution to fix Outlook sync issues is recreating Microsoft Outlook profile.
• You can stop any accounts from being brought over by adding them to the sync deny list.
• The causes of sync issues and local failures in Outlook are explained in this guide, along with practical troubleshooting and resolution techniques.
• Knowing the reasons behind the Outlook sync issues will help us to fix this problem and prevent issues in communication and workflow.
• Once you have completed the steps to fix Outlook sync errors, kindly check if the error has been fixed or not.
• 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.

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

Find out what to do if you are having issues with syncing users or groups from Microsoft 365. Once you have completed the steps to fix Outlook sync errors, kindly check if the error has been fixed or not. The error message in the Summary sheet of the Sync Summary spreadsheet attachment can also highlight the reason for this. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. To make sure there are no issues, click Test Account Settings to test the connection.

[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 online Outlook email repair utility the Users page and delete them as you see fit.

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

But setup is a little complicated and it can sometimes be difficult to identify the source of problems. We have resources to help you identify potential issues and fix them. The Support and Recovery Assistant, a tool provided by Microsoft, can identify and resolve common Outlook problems. It is capable of automatically identifying problems with account setups, sync, and fix Outlook after Windows update issues other typical mistakes.

Fixing problems with directory synchronization for Microsoft 365

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.



It is possible for a corrupted Outlook profile to impede synchronization. After these instructions, ensure the sync settings are correct and check everything is working well. This means that the authentication setup for your sync is no longer valid.



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.