The diagnostic will guide Outlook OST vs PST repair you to resolve various error conditions that can cause mailboxes to not be created. The most common cause of an out-of-date account is an incorrect password. In the notification bar at the top of the app, select Fix account.

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. Troubleshoot Office 365 Sync and Login Issues 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

Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. These are the only two I've seen have this issue and I was wondering if you've seen this and figured out a 'fix'? Tempted to create a Test Shared Mailbox, but thinking that wouldn't be an accurate test for inbound mail, etc. or just actually tested by the Users at all.

Check Antivirus and Firewall Settings

• This tool also helps users fix Outlook syncing issues by repairing OST or PST files and syncing the data smoothly.
• If restarting Outlook or fixing the profile doesn’t work, converting the OST file is often the next step.
• These syncing problems usually happen because of issues like a damaged Outlook profile, poor internet connection, or a corrupted OST file.
• The client has a computer off the domain at home that his work email is tied to and he has never had any of these issues in Cache mode with that device.
• Test other programs or websites to be sure Outlook is the only problem.
• However, with one particular client no matter what changes are made these sync issue still occur.
• This solution will be beneficial for users who are facing Outlook syncing issues because of corrupted PST or OST files.
• 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.

If you can sync your email when the firewall is turned off, you'll need to allow the Troubleshoot Office 365 Sync and Login 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

Check the software documentation to learn how to temporarily turn it off. There are various methods to resolve the Outlook sync issues, including manual and third-party solutions. Firstly, we will discuss a few manual methods to resolve this Outlook error and share the stepwise procedure of each method to successfully fix synchronization issues. Now, let us start with the manual processes to fix Outlook syncing errors. Firewalls and antivirus software might prevent you from syncing your email and calendar events. These syncing problems usually happen because of issues like a damaged Outlook profile, poor internet connection, or a corrupted OST file.