How to fix Outlook search not returning results or indexing slowly

Microsoft 365 & Office KB-373

Summary

This guide helps you troubleshoot and resolve: How to fix Outlook search not returning results or indexing slowly. Follow the steps below to fix the issue.

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Common Causes

If you are unable to find specific emails or notice that your search results are incomplete, it is likely that the Outlook search index has become corrupted or is still processing your data. This guide will walk you through the process of analysing your indexing status and rebuilding the search catalogue to restore full functionality.

Quick Fix Steps

Before performing a full index rebuild, try these simple steps to see if the issue resolves quickly:

Restart Outlook: Close the application completely and restart it to refresh the connection to the Windows Search service.
Check for Updates: Ensure your Office suite is up to date by going to File > Office Account > Update Options > Update Now.
Check the Search Scope: Ensure the dropdown next to the search bar is set to All Outlook Items or All Mailboxes rather than just Current Folder.

Detailed Instructions: Rebuilding the Search Index

If the quick fixes do not work, you will need to force Windows to re-analyse and re-index your mailbox data.

Step 1: Verify Indexing Status

Open Outlook and click into the Search bar at the top of the screen.
Select Search Tools from the top ribbon, then click Indexing Status.
A dialogue box will appear. If it says 0 items remaining, the index is complete. If it shows thousands of items remaining, Outlook is still processing your emails, and you should wait for this to finish.

Step 2: Rebuild the Index

Close Outlook.
Open the Windows Control Panel (you can search for this in the Start menu).
Set the View by option in the top right to Small icons.
Click on Indexing Options.
Click the Advanced button (this may require administrator permissions).
In the Index Settings tab, locate the Troubleshooting section and click Rebuild.
Click OK on the confirmation prompt.

Rebuilding the index can take several hours depending on the size of your mailbox. You can continue to use your computer, but search results will be incomplete until the process is finished.

Troubleshooting Advanced Issues

Checking the Windows Search Service

If the index is not updating at all, the underlying Windows service may be disabled.

Press Win + R on your keyboard, type services.msc, and press Enter.
Scroll down to find Windows Search.
Right-click Windows Search and select Properties.
Ensure the Startup type is set to Automatic (Delayed Start).
If the service is stopped, click Start, then click OK.

Repairing the Outlook Data File

Corruption within your .ost or .pst file can prevent the indexer from reading your emails. If you suspect file corruption, refer to our guide on Backing Up and Restoring Outlook Data Files (.pst/.ost).

Do not attempt to manually delete files from the AppData folder unless directed by a technician, as this can lead to permanent data loss of local-only folders.

Checking for Conflicting Software

Some third-party antivirus or security software can interfere with the indexing process. Try temporarily disabling your security software to see if the indexing speed increases.

Related Guides

If your search is still not returning results after a full rebuild, please Open a Ticket for further technical assistance.

Still Having Issues?

Need more help? If the issue persists after trying these steps, please open a support ticket and our team will assist you.

💻 Open a Ticket