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 fix MFA prompts not working beneficial for users who are facing Outlook syncing issues because of corrupted PST or OST files.

Turn off Windows Defender Security Center

If the size of your .ost file is close to the limit, you could try increasing the limit on your client, restart Outlook and see if there is any difference. guide to Office 365 sign-in errors I’ve unchecked download shared folders when setting up a new Outlook profile. After performing these steps, Outlook’s all folders will be synced to the server. If this method doesn’t work for you, navigate to other solutions. Select the button below to launch a diagnostic in the Microsoft 365 admin center.

Check if two-factor authentication is turned on for your account

It is possible for a corrupted Outlook profile to impede synchronization. Test other programs or websites to be sure Outlook is the only problem. If the connection is poor, consider restarting your modem/router or moving to a more reliable network. 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 is not from a trusted certifying authority." Check with your email provider for instructions about how to create an app password for your email account.

Check Antivirus and Firewall Settings

• It is capable of automatically identifying problems with account setups, sync, and other typical mistakes.
• Users can also try its free demo version in their system and process the first 50 items from each folder freely.
• Outlook sync issues can be because of corrupted Outlook OST or PST files.
• This software allows users to process numerous OST files at once without any size limitations.
• Knowing the reasons behind the Outlook sync issues will help us to fix this problem and prevent issues in communication and workflow.
• If two-factor authentication is turned on for your account, you'll need to create an app password for that account.
• However I do not use Outlook on it as much as I do on my desktop.

If you can sync your email when the firewall is turned off, you'll need to allow the modern authentication troubleshooting 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.

Free Methods to Remove Duplicate Items in Outlook 2016

The Mail and Calendar apps for Windows 10 don't support two-factor authentication. If two-factor authentication is turned on for your account, you'll need to create an app password for that account. An app password is used instead of your normal account password for apps that don't support two-factor authentication. Before you begin, make sure that your device has the latest operating system and app updates. Try the general troubleshooting solutions in Troubleshooting Mail and Calendar apps for Windows 10. I regret that you are experiencing issues with your Microsoft Outlook slow synchronizing inbox message, and need help speeding up.