You can close the wizard at this point as you do not need to complete it for re-authentication to take effect. You should run a test sync after re-authenticating the sync to ensure it is working. Now, we will verify the server settings to fix the Outlook synchronization error. The sync will fail if the groups you selected to load users from no longer exist in Azure AD.

Common Causes of Sync Issues in Outlook

Knowing the reasons behind the Outlook sync issues will help us to fix this problem and prevent issues in communication and workflow. 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. Find out what to do if you are having issues with syncing users or groups from Microsoft 365. It is possible for a corrupted Outlook profile to impede synchronization.

Fixing problems with directory synchronization for Microsoft 365

Another which is shown below, is a user opens a new message, or replies to one, and lets it sit for a while. When they go back to the message and press Outlook profile repair and recovery steps send they get an error that the message has been deleted. Ive repaired the OST and changed cache mode to only cache 1 year.

• Sync failure alerts do not always include a full summary or attachment, you can run a test sync to obtain this data.
• These syncing problems usually happen because of issues like a damaged Outlook profile, poor internet connection, or a corrupted OST file.
• 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.
• The M365 sync establishes a synced dataset based on your M365 data and the filtering configuration of your sync.
• Both of our authentication methods can fail if the Enterprise Applications entry for the sync in Azure AD is deleted or if it has had its permissions modified.
• We have resources to help you identify potential issues and fix them.

Use the Microsoft Support and Recovery Assistant

If you are still facing this issue, kindly follow the solutions below to fix the sync issues in Outlook. 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.

How to Fix Outlook Sync Issues in Windows?

The Support and Recovery Assistant, a tool provided by Microsoft, can identify and resolve common Outlook problems. rebuild Outlook data file quickly It is capable of automatically identifying problems with account setups, sync, and other typical mistakes. To solve your Outlook issues, download the application from the Microsoft website and follow the directions.

Mailing Address

You can view your inactive users on the Users page and delete them as you see fit. Similarly you should review fix Outlook after Windows update issues the Users Deactivated sheet on the sync summary spreadsheet attachment as you can also delete these users to bring your total down. I have multiple users experiencing sync errors with Outlook and office365.





The error message in the Summary sheet of the Sync Summary spreadsheet attachment can also highlight the reason for this. This means that the authentication setup for your sync is no longer valid. This can happen for the a number reasons particularly if your sync authenticates using Delegated Permissions.



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. Users can also try its free demo version in their system and process the first 50 items from each folder freely. Always make sure your profile and settings are set up correctly, your software is up to date, and your connection is steady.