Incorrect Outlook settings can also be one of the reasons behind Outlook synchronization errors. The Support and Recovery Assistant, a tool provided by Microsoft, can identify and resolve common Outlook problems. It is capable of automatically Fix Outlook and Office 365 Errors 2025 identifying problems with account setups, sync, and other typical mistakes. To solve your Outlook issues, download the application from the Microsoft website and follow the directions. Outlook’s ability to connect to the mail server may be blocked by firewalls or antivirus software.

Turn off Windows Defender Security Center

It also provides the option to export the Outlook OST file into Office 365 and Live Exchange mailboxes. This software also has a splitter option to split large-sized PST files into smaller ones, helping users prevent oversized PST file issues. Outlook sync issues can be because of corrupted Outlook OST or PST files. Therefore, now we will know the steps to repair the Outlook data file. We’ve Fix Outlook and Office365 Sync Issues had sync issues with employees from time to time however, re doing the mail profile or wiping the Windows profile usually fixes it. In some cases setting up a new computer replacement was the only option to fix these odd Outlook Sync issues.

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

• Windows Defender Security Center is free security software that's included with Windows 10.
• In some cases setting up a new computer replacement was the only option to fix these odd Outlook Sync issues.
• This blog talks about the causes behind Outlook synchronization errors and a few solutions to fix Outlook sync issues.
• 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.
• We have shared five manual methods in this blog to resolve the Outlook syncing errors.
• However, I cannot find any reason why his account would do this only on our domain nothing is blocking our connection to Office 365.

You'll have the option to do that on your "My Questions" page by clicking the heart icon labeled My Favorite. Please reply with your results when you have completed the steps above. Additionally, you might want to make a new profile and make it the default to see if it fixes the problem. However, his OST file is not anywhere near that size it’s about 5GB. I was wondering if anyone had some insight into an issue I am having with credential loop in Microsoft 365 a client. The service typically takes less than 30 minutes to provision a user or to sync changes for a user.

Free Methods to Remove Duplicate Items in Outlook 2016

If you're using an Exchange account that requires advanced settings, you'll need to remove the account and add it again using advanced settings. To add the account using advanced settings, see Add an account using advanced setup. Knowing the reasons behind the Outlook sync issues will help us to fix this problem and prevent issues in communication and workflow. If you still can't sync your email after removing your account and adding it again, you might need to add the account using advanced setup. If I check the sync log I see a lot of sync errors for Inbox, sent items and a few other folders.