The other solution to fix Outlook sync issues is recreating Microsoft Outlook profile. Follow each step carefully to resolve synchronization errors. Sometimes an error appears in the Mail and Calendar apps when mailbox not updating on IMAP the apps try to sync new email or calendar events. We’ve had sync issues with employees from time to time however, re doing the mail profile or wiping the Windows profile usually fixes it.

Method 4: Recreating the Outlook Profile

However once I joined this computer back to the domain and let it sit for a few days it was also working fine. Once the client started using Outlook again after some time has passed the issue had come back. I’ve tried to set cache mode from 1 year all the way down to a few days. If your password isn't the problem, you might have a certificate error. If so, you'll see a message that says, "There is a problem with the server's security certificate. The security certificate Outlook Stuck on Synchronizing Folders is not from a trusted certifying authority."

Check the connectivity to your email server

• This software also has a splitter option to split large-sized PST files into smaller ones, helping users prevent oversized PST file issues.
• 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.
• It is possible for a corrupted Outlook profile to impede synchronization.
• If you're using an Outlook.com, Microsoft 365, or Exchange account, you won't have advanced mailbox settings unless the account was set up using advanced setup.
• Apart from this, we also discuss the Shoviv OST to PST Converter Tool, a professional way to repair, recover, and convert Outlook data files.
• In some cases setting up a new computer replacement was the only option to fix these odd Outlook Sync issues.
• Here is the strange part I tried to remove the computer from the domain and have Outlook run from a local account for a few days.

You'll also receive a mail (to the alternate email and to your admin email) from Microsoft Outlook Not Sending or Receiving Email 365 that indicates your tenant has encountered directory synchronization errors. For details see Identify directory synchronization errors in Microsoft 365. I still have it turned on on my laptop and it has not shown any issues yet.

Methods to fix Microsoft Outlook syncing error

If the connection is poor, consider restarting your modem/router or moving to a more reliable network. After these instructions, ensure the sync settings are correct and check everything is working well. I’m at wits end and Microsoft stopped helping me because they feel the problem is on our end. However, I cannot find any reason why his account would do this only on our domain nothing is blocking our connection to Office 365. Here is the strange part I tried to remove the computer from the domain and have Outlook run from a local account for a few days.

Microsoft Outlook Sync issues

To make sure there are no issues, click Test Account Settings to test the connection. It is possible for a corrupted Outlook profile to impede synchronization. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. If the problems do not occur in safe mode, its most likely an add-in causing grief. I’ve been in contact with Microsoft they had me migrate his account\data to another server this did not fix it.