How to Fix Sync Issues and Local Failures in Outlook?

Microsoft Outlook creates a local cache (.ost file) to store all the mail items, such as messages, attachments, contacts, etc. When online and connected to server, Outlook synchronizes the OST file with mailbox on the server and vice-versa. This way mailbox items in OST and on server remain up-to-date. Sometimes, users face sync issues between the Outlook and the server.

When there is a problem in synchronization, Outlook may fail to send or receive any new emails or meeting invites. This can also lead to the following problems:

• Delays in communication.
• Missing emails.
• Scheduled meetings or invitations may not reflect accurately.
• Outdated contacts or contacts may not reflect.

Let’s understand the reasons for the sync issues in Outlook and the solutions to troubleshoot them to ensure uninterrupted workflow.

Reasons for Sync Issues and Local Failures in Outlook

There are several reasons that may lead to the synchronization issues and local failures in Outlook, such as:

1. Poor internet connection or network interruption.
2. Mailbox server is not available due to maintenance work or outages.
3. Inaccessible or oversized Outlook data file (OST).
4. Incompatible or faulty add-ins interfering with Outlook’s functionality.
5. Incorrect email account settings or configuration.
6. Outdated Outlook application.
7. Damaged Outlook or MS Office program files.
8. Hardware issues or file system errors.

Solutions to Fix Sync Issues and Local Failures in Outlook

Sync issues indicate that Outlook is not able to update changes to or from the mailbox server whereas the local failure indicates problem with the Outlook client, system, or the Outlook data file. Below we have mentioned some solutions that you can follow to resolve such issues.

1. Check Internet Connection

To ensure proper synchronization of mail items, you must ensure that you have a working and stable internet connection. To fix any issues related to network or connectivity,

• Restart router or modem to reset the connection.
• If possible, connect to a different wireless (Wi-Fi) network or use your smartphone hotspot to rule out local network issues.
• Switch to a wired connection for more reliable internet access as Wi-Fi is prone to interference caused by other radio waves.
• Change the DNS to public DNS, such as 8.8.8.8 and 8.8.4.4

2. Update Outlook

Ensure that you are running the latest version of Outlook as it helps overcome any bugs or issues that might be causing sync issues or local failure. The steps to update Outlook application are as follows:

• Open Outlook and go to File > Office Account > Update Options.
• From the available options, choose Update Now.

• If a new update is available, download and install it.

After the update, restart system and then launch Outlook to check if the sync issues and local failures are resolved.

3. Check/Update Credentials

Outdated or expired email credentials can also lead to sync issues as Outlook fails to authenticate and update the mail items. If you have recently changed or updated the password,

• Go to Send/Receive tab and click Type Exchange Password & Connect.

• Type your updated password. In case you don’t know, reach out to the administrator to get your updated password.

4. Check Server Status

Make sure that the server is online and available. It might happen that the server is down due to maintenance or power failure. To check if the server is online and available,

• Open any web browser, such as Chrome or Edge.
• Go to the Outlook web app page URL and sign in using your account.
• If you are able to login and access mail items, the server is online. Otherwise, wait and try after sometime. You may also contact the administrator or email service provider for more details.

5. Disable/Remove Faulty or Problematic Add-Ins

Faulty or problematic third-party add-ins can cause various issues in Outlook. In such a case, you can find and disable the faulty add-ins. Follow the below steps:

• Close Outlook and press Windows + R keys.
• Type outlook.exe /safe and press Enter to launch Outlook in safe mode.

• Go to Send/Receive tab and click Update Folders. If all mail folders synchronize, then it indicates problem with one or more add-ins.
• Now, click File > Options and select Add-ins.
• Click the Go button and unselect all the add-ins.
• Click OK to disable all the add-ins.

• Once the add-ins are disabled, restart Outlook normally.

Now, to find which add-in is causing the issues,

• Enable one add-in at a time and restart Outlook.
• Repeat the above step until you see the sync issues or local failure.
• Once identified, remove or uninstall the faulty or incompatible add-in to resolve the issue.

6. Repair Office Installation

Problem with the Outlook/MS Office installation can also cause sync issues in Outlook. You can repair the MS Office program to fix any issues with the installation. Here are the steps:

• Open Settings on your Windows system.

• Choose Apps & features. 

• Find and click on Microsoft Office application. Choose the Modify option.

• Select the Quick Repair option and click Repair.

If Quick Repair fails to fix the problem, start the process again and choose Online Repair option and complete the repair wizard.

• Click on the Repair button when the following message is displayed.

• Wait for the repair process to finish.

• After this, restart your system.

In case repair does not work, you can reinstall the MS Office program.

7. Reduce Data File Size

A large or oversized OST file may also lead to syncing issues. Thus, you can reduce the size of OST file and mailbox by archiving old emails, and emptying the Deleted Items and Trash or SPAM folders. The steps to archive mail items are as follows:

• In Outlook, go to File > Info > Cleanup Tools > Archive or File > Info > Tools > Clean up old items based on your Outlook version.

• Click the Archive this folder and all subfolders option and choose the folder you want to archive.
• In the Archive items older than field, you need to choose or enter a date.

• Click Browse to choose a location where you want to save this archive PST file and click OK.

You can repeat this process to create multiple local archive .pst files.

8. Use Microsoft Support and Recovery Assistant (MSARA)

MSARA is a utility provided by Microsoft that helps you run a few tests on your system, identifies the underlying problems, and then provides the best solutions to fix the problems. Here’s how to use this tool:

• Download Microsoft Support and Recovery Assistant setup and launch it. Click ‘Install.’

• After installation, click ‘I agree.’

• Select Outlook from the options and click ‘Next.’

• Select Sync Issues or Other Problems and click Next.
• Click Yes and then click Next.
• Complete the wizard and apply the solutions to troubleshoot and fix the issues.

9. Rebuild OST

Inaccessible or damaged OST file can also lead to sync issues and local failures as Outlook may find it difficult to read or store new information to/from the OST file. However, you can recreate a new OST file by following these steps:

• Close Outlook (if running).
• Press Windows + R, type %localappdata%/Microsoft/Outlook,and press the Enter key or click OK. This opens the OST file location.
• Here, rename the OST file, which is associated with your email account. Add the .bak suffix to the name. For instance, if the file name is joe@abc.com.ost, rename it to joe@abc.com.ost.bak. 

• Now, close all the windows and start Outlook.
• As soon as Outlook starts, you will see a new OST file being created. Outlook will download all the mail items from the mailbox server to the new OST file.

In case you find missing mail items in new OST file after synchronization is done, you can extract and restore those missing items from the backup OST file. For this, you can use a professional OST to PST converter software, like Stellar Converter for OST. It can extract mail items, such as emails, contacts, attachments, etc. from your backup OST file and save them to a PST file, which you can easily import into your Outlook. It can also convert orphaned or inaccessible OST file (up to 50 GB) in just a few simple steps. You also get option to export the mail items from the OST file directly to Microsoft 365 or live Exchange Server.

Conclusion

Synchronization issues and local failures in Outlook can lead to missed or outdated mail items, appointments, contacts, etc. This can disrupt your email communication and workflow as you may fail to send or receive new emails. This guide helps you understand the reasons for sync issues and local failures in Outlook and discusses the solutions to effectively troubleshoot and resolve such issues. If your OST file becomes inaccessible or orphaned, you can use an advanced OST to PST converter software, such as Stellar Converter for OST to extract and restore all mail items to a PST file.

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About The Author

Ravi Singh

Ravi Singh is a Senior Writer at Stellar®. He is an expert Tech Explainer, IoT enthusiast, and a passionate nerd with over 7 years of experience in technical writing. He writes about Microsoft Exchange, Microsoft 365, Email Migration, Linux, Windows, Mac, DIY Tech, and Smart Home. Ravi spends most of his weekends working with IoT (DIY Smart Home) devices and playing Overwatch. He is also a solo traveler who loves hiking and exploring new trails.