If the connection is poor, consider restarting your modem/router or moving to a more reliable network. You will need to have the correct privileges set on your Azure account in order to set up the M365 sync. We're in the process of migrating from On-Premise Exchange to O365. I have a couple of Users and a Shared Mailbox that were migrated and both Users are experiencing issues with the Shared Mailbox updating on a regular basis. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Additionally, you might want to make a new profile and make it the default to see if it fixes the problem.

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 work offline mode stuck send they get an error that the message has been deleted. Ive repaired the OST and changed cache mode to only cache 1 year.

• To get the sync working you will either need to delete users or have the user limit on your account increased.
• Users can also convert OST files into various file formats, including PST, HTML, EML, MSG, vCard, etc.
• The error message in the Summary sheet of the Sync Summary spreadsheet attachment can also highlight the reason for this.
• I have multiple users experiencing sync errors with Outlook and office365.
• If it does, you might need to include Outlook exceptions in the settings of your security program.
• You will need to have the correct privileges set on your Azure account in order to set up the M365 sync.

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 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 clear Outlook credentials manager recycle bin of users who you can delete when you no longer need them.





If this method doesn’t work for you, navigate to other solutions. 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. 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. You can do this in the Microsoft Troubleshoot Office 365 Sync and Login Issues 365 Sync Wizard on the configuration page of your platform settings. Once you have completed the steps to fix Outlook sync errors, kindly check if the error has been fixed or not.

What should I do if my sync fails because it can't find any users?

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 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.