If you can sync your email when the firewall is turned off, you'll need to allow the Mail and Calendar apps through the firewall. Windows Defender Security Center is free security software that's included with Windows 10. If you haven't installed alternative security software, you should temporarily turn off Windows Defender Security Center. Test other mailbox not updating on IMAP programs or websites to be sure Outlook is the only problem.

Method 4: Recreating the Outlook Profile

If you still can't sync your email after removing your account and adding it again, you might need clear Outlook credentials manager to add the account using advanced setup. For more information, see Add an account using advanced setup. Now, we will verify the server settings to fix the Outlook synchronization error. Knowing the reasons behind the Outlook sync issues will help us to fix this problem and prevent issues in communication and workflow.

Check the connectivity to your email server

• We have resources to help you identify potential issues and fix them.
• I’ve unchecked download shared folders when setting up a new Outlook profile.
• I’ve been in contact with Microsoft they had me migrate his account\data to another server this did not fix it.
• Before you begin, make sure that your device has the latest operating system and app updates.
• Below are the steps I’ve taken to try to resolve this issue.
• Firewalls and antivirus software might prevent you from syncing your email and calendar events.
• If so, you'll see a message that says, "There is a problem with the server's security certificate. The security certificate is not from a trusted certifying authority."
• This solution will be beneficial for users who are facing Outlook syncing issues because of corrupted PST or OST files.

However, his OST file is not anywhere near that size it’s about 5GB. I was wondering if anyone had some insight into an issue I am having with a client. Additionally, you might want to make a new profile and make it the default to see if it fixes the problem. Create your account Outlook Login Issues Troubleshooting and connect with a world of communities.

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

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.