This tool also helps users fix Outlook syncing issues by repairing OST or PST files and syncing the data smoothly. 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 Troubleshoot Office 365 Sync and Login Issues 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. I have multiple users experiencing sync errors with Outlook and office365.

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 Repair Outlook Profile Online is not from a trusted certifying authority."

Check the connectivity to your email server

• Before finding solutions, we suggest that users check their internet connection.
• This software allows users to process numerous OST files at once without any size limitations.
• After the files get repaired, restart the Outlook program to ensure that the Outlook syncing issues are resolved or not.
• If users are facing syncing issues in Outlook due to corrupt Outlook data files, they must choose a professional tool, like Shoviv OST to PST Converter Tool.
• After performing these steps, Outlook’s all folders will be synced to the server.
• The Mail and Calendar apps for Windows 10 don't support two-factor authentication.
• Moreover, it maintains the folder hierarchy and metaproperties of the data when processing Outlook data files.
• This can happen for days at a time, and then disappear for a day or 2, only to appear again.

You'll also receive a mail (to the alternate email and to your admin email) from Microsoft How To Fix Outlook Not Opening Today 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

I ran the PSTscan tool to check for anomalies on the OST file (which it found and repaired but the issue still occurs). However, with one particular client no matter what changes are made these sync issue still occur. We're sorry you're having problems with the Mail and Calendar apps for Windows 10. To fix the issue, please try each of the following solutions in order.

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.