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

Typically this is because the selected groups have been deleted from Azure AD since the M365 sync was configured on your account. 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, you might need to include Outlook exceptions in the settings of your security program. After viewing, see fixing problems with directory synchronization for Microsoft 365 to correct any identified issues. After performing these steps, Outlook’s all folders will be synced to the server.

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 OST vs PST repair send they get an error that the message has been deleted. Ive repaired the OST and changed cache mode to only cache 1 year.

• 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.
• After the files get repaired, restart the Outlook program to ensure that the Outlook syncing issues are resolved or not.
• Additionally, you might want to make a new profile and make it the default to see if it fixes the problem.
• Outlook sync issues can be because of corrupted Outlook OST or PST files.
• Firstly, we will discuss a few manual methods to resolve this Outlook error and share the stepwise procedure of each method to successfully fix synchronization issues.

Use the Microsoft Support and Recovery Assistant

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. 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.

How to Fix Outlook Sync Issues in Windows?

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 sync does not delete users but rather sets them to inactive. The idea is to provide a expert Outlook tips by FixTechGuide recycle bin of users who you can delete when you no longer need them.

Mailing Address

You can view your inactive users on the Users page and delete them as you see fit. Similarly you should review online Outlook email repair utility 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.

Fix Sync Issues and Local Failures in Microsoft Outlook: Problem Resolved!

This tool also helps users fix Outlook syncing issues by repairing OST or PST files and syncing the data smoothly. There are various methods to resolve the Outlook sync issues, including manual and third-party solutions. Firstly, we will discuss a few manual methods to resolve this Outlook error and share the stepwise procedure of each method to successfully fix synchronization issues. Now, let us start with the manual processes to fix Outlook syncing errors.