If it didn’t, a few targeted checks usually restore access—no need to keep resetting your password over and over. The other solution to fix Outlook sync issues is recreating Microsoft Outlook profile. We start by checking that Azure AD Connect is running and password sync is enabled. If it’s in Staging Mode or a recent change didn’t trigger a full sync, passwords won’t update in Microsoft 365.

• The other solution to fix Outlook sync issues is recreating Microsoft Outlook profile.
• 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.
• It also provides the option to export the Outlook OST file into Office 365 and Live Exchange mailboxes.
• We tell users to sign out completely and remove stored credentials from Windows Credential Manager or their device’s keychain.
• In these cases, direct escalation to Microsoft or working with a Microsoft CSP partner, such as TrustedTech, can expedite resolution and minimize downtime.
• We usually check settings like Password Writeback, Synchronization Rules Editor, and Service Account Permissions to spot misconfigurations.

Troubleshooting Microsoft 365 sync issues

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. You'll also receive a mail (to the alternate email and to your admin email) from Microsoft 365 that indicates your tenant has encountered directory synchronization errors. For details see Identify directory synchronization errors in Microsoft 365. We also check the synchronization scheduler to confirm delta and full sync cycles finish successfully. We check that Microsoft Entra Connect (Azure AD Connect) runs the latest version and password sync is on.

Common Reasons Behind Outlook Sync Issues

If the old password still works, the reset probably hasn’t synced. To resolve these issues you should run the steps in this article and check diagnose Office activation conflicts whether the groups in your sync's filtering preference contain users in Azure AD. The simplest way to resolve authentication issues is to rerun the authentication process by clicking the Sign in with Microsoft on the Microsoft 365 settings page.

Address

Now, we will verify the server settings to fix the Outlook synchronization error. Once you have completed the steps to fix Outlook sync errors, kindly check if the error has been fixed or not. The M365 sync establishes a synced dataset based on your M365 data and the filtering configuration of your sync.

Get Expert Help from TrustedTech

We show users how to reset passwords using approved methods like the Microsoft 365 portal or self-service password reset (SSPR). If someone changes their password only in the cloud or just on a local system, things can get out of sync pretty quickly. Bad settings in Azure AD Connect cause lots of password sync failures. If password writeback isn’t enabled or the service account doesn’t have the right permissions, new passwords won’t update in Active Directory. That leaves people locked out with their new password on the cloud but not locally. 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.

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

We also scan Event Viewer logs under Applications and Services credential loop in Microsoft 365 Logs → Directory Synchronization for Event IDs like 650–657 (for sync activity). Errors like Event ID 611 point to invalid replication data or outdated software. The error message in the Summary sheet of the Sync Summary spreadsheet attachment can also highlight the reason for this.



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.

To get the sync working you will either need to delete users or have the user limit on your account increased. Find out what to do if you are having issues with syncing users or groups from Microsoft 365. Real-time collaboration is at the core of Microsoft 365; however, issues can arise due to permissions, software version conflicts, or connectivity problems. 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.



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.

Keeping Azure AD Connect up to disable faulty add-ins in Outlook date and testing sync regularly helps password resets flow like they’re supposed to. Password sync usually fails when credentials don’t update between Microsoft Entra ID (Azure AD) and your on-premises Active Directory. Most of the time, the problem comes from timing delays, configuration mistakes, or cached credentials on devices that don’t pick up new passwords. Outdated credentials get stuck on devices, password sync gets turned off, or Microsoft Entra Connect just doesn’t update like it should. Here’s a step-by-step approach to help you spot the issue, fix it, and avoid these sync delays down the road.