I have multiple users experiencing sync errors with Outlook and office365. Another which is mailbox not updating on IMAP shown below, is a user opens a new message, or replies to one, and lets it sit for a while. When they go back to the message and press send they get an error that the message has been deleted. Ive repaired the OST and changed cache mode to only cache 1 year. Incorrect Outlook settings can also be one of the reasons behind Outlook synchronization errors.

• Outlook sync issues can be because of corrupted Outlook OST or PST files.
• If you are still facing this issue, kindly follow the solutions below to fix the sync issues in Outlook.
• If I check the sync log I see a lot of sync errors for Inbox, sent items and a few other folders.
• I’m at wits end and Microsoft stopped helping me because they feel the problem is on our end.
• Always make sure your profile and settings are set up correctly, your software is up to date, and your connection is steady.
• If the problems do not occur in safe mode, its most likely an add-in causing grief.

7 Customer support

If the problems do not occur in safe mode, its most likely an add-in causing grief. I’ve been in contact with Microsoft they had me migrate his account\data to another server this did not fix it. I’ve tried the Microsoft office uninstall tool provided by Microsoft (which deletes more items then just control panel uninstall).

Fix Sync Issues and Local Failures in Microsoft Outlook: Problem Resolved!

However I do not use Outlook on it as much as I do on my desktop. Outlook’s ability to connect to the mail server may be blocked by firewalls or antivirus software. After you’re satisfied, turn off your firewall or antivirus program for a while.

Disable Add-ins

But setup is a little complicated and it can sometimes be difficult to identify the source of problems. We have resources to help you identify potential issues and fix them. The Support and Recovery Assistant, a tool provided by Microsoft, can identify and resolve common Outlook problems.

Check for Local Failures

If this method doesn’t work for you, navigate to other solutions. Knowing the reasons behind the Outlook sync issues will help us to fix this problem and prevent issues in communication and workflow. There can be several reasons for the Outlook synchronization error. Before we know the solutions, we will understand a few common causes of the Outlook Office 365 Sync Errors Fix sync problem. 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. I’ve unchecked download shared folders when setting up a new 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.

Repair Your Outlook Profile

The other solution to fix Outlook sync issues is recreating Microsoft Outlook profile. Follow each step carefully to resolve synchronization errors. There are various methods to resolve the Outlook sync issues, including manual and third-party solutions. Firstly, we will discuss a few manual methods Fix Outlook Not Opening After Windows Update 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.