How to Deal with Outlook Sync Issues: Tips and Tricks for Hassle-Free Solution

When you create a profile in Outlook using Exchange Server, IMAP, or Microsoft 365 account, an Offline Storage Table (OST) file is automatically created by Outlook on the local system. The offline storage file contains all your mailbox items such as emails, attachments, contacts, calendar, etc. The OST file is synchronized with the server mailbox at all times when the Outlook is connected to server and internet and thus keeps the mailbox information up-to-date.

There are instances when you have an issue where the Outlook application fails to synchronize the information of OST file with the server mailbox. This can result in a time lag in sending or receiving messages or even result in outdated contacts and other information. In this article, we will analyze the reasons that could cause the sync issue in Outlook and see how they can be addressed.

Common Reasons for the Outlook Sync Issues

The following are some of the common causes which can result in Outlook syncing issues:

• Poor or no internet connectivity 
• Incorrect Outlook settings and preferences
• Outdated Outlook application 
• Mailbox is full 
• Low storage space on disk
• Faulty third-party add-ins
• Corrupt Outlook profile
• Inconsistent OST file  

Solutions to Resolve the Outlook Sync Issues

For uninterrupted sync between Outlook and server mailbox, there has to be a stable internet connection. So, first check your internet connection is stable and in working condition. You can do this by opening any random websites or internet applications. If you still face sync issues, then execute the following troubleshooting steps and solutions.

1. Verify Outlook Account Settings

If your Outlook account settings are incorrect, then the software may fail to synchronize the mail items between the server and your application. Hence, make sure that your email account is correctly set up. To achieve this,

• Open Outlook.
• Navigate to File > Account Settings > Account Settings.
• Choose your email account and click on Change.
• In the Server Settings window, click on More Settings and then Advanced.
• Ensure the in and out server settings are correct. Ensure the server name and login credentials are correct.
• After making the changes, click Next > Done.

Now restart Outlook and verify if the sync is operating.

2. Disable Faulty Third-Party Add-Ins

Incompatible or broken third-party add-ons in Outlook could also be causing the sync issues in Outlook. To test this, open Outlook in safe mode with the Windows + R keys and enter outlook.exe /safe. If Outlook starts fine in safe mode, then it is certain that some defective add-in is causing the problem. Temporarily disable the add-ins by going to File > Options > Add-Ins > COM Add-ins > Go. Then, close Outlook in the usual manner and turn on one add-in at a time to find the errant add-in.

3. Check and Disable Work Offline Mode

You might have unintentionally turned on the Work Offline mode. In the Work Offline mode, the mailbox server is not connected with the Outlook application. So, check and disable the Work Offline mode, if it is already turned on. To check this:

• Open Outlook and then click on the Send/Receive tab..

• Click the Work Offline button at the top right to come back online.

• Now, check the status bar at the bottom. It should show ‘Connected to Exchange Server.’

4. Fix Your Outlook Profile

If your Outlook profile is corrupted or damaged, it can also cause sync issues. You can repair the Outlook profile to fix this problem. To repair your profile, follow these steps:

• Open Outlook and click on the File tab.
• Go to Account Settings > Account Settings.

• On the Account Settings window, choose your email account/profile and click Repair. 

• Outlook will start the repair process. Once it’s done, restart the application.  

5. Create a New Outlook Profile

If profile repair does not work, you can create a new Outlook profile. Here's how:

• Open the Control Panel.
• Go to User Accounts > Mail.
• Click Show Profiles and then click on Add.
• Enter a name for the new profile and click OK.
• Sign in with the same email account credentials and then click Next > Finish.
• From the dropdown menu, select your new profile and check the box Always use this profile.
• Click Apply > OK. 

6. Repair or Reinstall Outlook/Microsoft Office 

Corruption in Outlook/MS Office installation files can also lead to problems with syncing in Outlook. You can repair the Outlook/MS Office program to resolve the problem. Here is how you can do this:

• Open the Control Panel.
• Move to Programs and Features and click on Uninstall a program.
• Look for your version of Microsoft Office in the list, select it, and click on Change. This will open the Repair Wizard.
• Select Repair and continue with the on-screen prompts to complete.
• Restart your PC and open Outlook to see if the issue is resolved after repairing.

If repairing was unsuccessful, then you reinstall MS Office program from scratch.

7. Rebuild the Outlook OST File

If the above steps did not work, then there is something amiss with the Outlook data (OST) file itself. On that occasion, you are able to rebuild the OST file. To do so:

• Close Outlook.
• Press Windows + R to invoke the Run dialog box.
• In the Run dialog box, enter %localappdata%\\\\Microsoft\\\\Outlook and click OK.
• Find your OST file and rename it by adding the .bak extension. This will save a copy of the OST file.
• Delete the original OST file and start Outlook.

When Outlook starts, it won’t find the OST file and then automatically creates a new one and re-sync all your mailbox data from the server. 

After rebuilding the OST file, make sure to check for any missing mailbox items in the new file. In case you found any, then use an OST to PST converter tool, such as Stellar Converter for OST to extract the missing items from the backup OST file. This tool saves the extracted mailbox items to a PST file, which you can import into Outlook using the Import/Export wizard.

This tool is designed to convert inaccessible or orphaned OST files into PST format while keeping the mailbox data intact. It can also save the OST file data in other formats, such as MSG, EML, RTF, PDF, and HTML.

Conclusion

Sync issues in Outlook can prevent you from sending/receiving emails, thus inhibiting your work. You can resolve the sync issues in Outlook using the above solutions. If there is something wrong with OST file, then back up OST file and recreate it. If you have found any missing items in new OST file, then use an advanced OST to PST converter tool, like Stellar Converter for OST, to retrieve the missing items from back-up OST file.