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 there's a feature you think is missing from the Mail and FixTechGuide Office 365 troubleshooting Calendar apps, or if a feature in isn't working properly, you can provide feedback directly to the Mail and Calendar team. Two-factor authentication helps protect your account by making it more difficult for someone else to sign in. It verifies your identity using your password and a contact method (also known as security info). If you would like to ask me another question in the future or follow up on your current question, you can add me as a favorite Expert.

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

Once the client started using Outlook again after some time has passed the issue had come back. I ran the PSTscan tool to check for anomalies on the OST file (which it found and repaired but the issue still occurs). I’ve tried to set cache mode from 1 year all the way down to a few days.

Check Antivirus and Firewall Settings

• It is capable of automatically identifying problems with account setups, sync, and other typical mistakes.
• 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.
• Third-party firewalls or antivirus software might prevent you from syncing your email and calendar events.
• 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 Fix Outlook and Office365 Sync Issues 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.