Outlook 365 Search Not Working? The Ultimate 2024 Troubleshooting Guide

In the modern workplace, your email archive is your external brain. When Outlook 365 search is not working, it’s more than a minor glitch—it’s a major roadblock. Whether your search returns “No Results,” the search bar is completely unresponsive, or it refuses to show emails from the last 24 hours, you are not alone. This issue is one of the most common complaints among Microsoft 365 users.

This guide provides 10+ actionable solutions to restore your search functionality. We will cover everything from simple settings tweaks to advanced registry repairs.

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Table of Contents

1. The Quick Snippet Fix: Rebuild Your Index
2. Why Outlook Search Fails: Common Causes
3. Method 1: Update Microsoft 365 and Windows
4. Method 2: Check the Windows Search Service
5. Method 3: Include Outlook in Indexing Locations
6. Method 4: Repair Your Outlook Data Files (.PST/.OST)
7. Method 5: Use the Office Online Repair Tool
8. Method 6: Adjust the Sync Slider Settings
9. Method 7: Disable Conflicting Add-ins
10. Method 8: Advanced Registry Fix for Search
11. Method 9: Create a New Outlook Profile
12. Method 10: Check Group Policy Settings
13. Frequently Asked Questions (20 FAQs)

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The Quick Snippet Fix: Rebuild Your Index

If you need an immediate solution, rebuilding the search index is the most successful fix for 90% of users.

1. Open Outlook and click File > Options.
2. Select Search from the left-hand menu.
3. Click on Indexing Options, then click Advanced.
4. Under the Index Settings tab, click the Rebuild button.
5. Click OK and wait. This process can take time depending on your mailbox size.

For more detailed instructions, you can visit the official Microsoft Support page on indexing.

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Why Outlook Search Fails: Common Causes

Understanding the root cause can help you choose the right fix. Outlook search usually fails due to:

• Corrupted Index: The “map” Outlook uses to find emails is broken.
• Disabled Services: The Windows Search background process has stopped.
• Large Data Files: If your .ost or .pst file is over 50GB, indexing often hangs.
• Software Conflicts: Third-party antivirus or older add-ins interfering with the search crawl.

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Method 1: Update Microsoft 365 and Windows

Microsoft frequently releases “silent” patches for search bugs.

• Update Outlook: Go to File > Office Account > Update Options > Update Now.
• Update Windows: Go to Settings > Windows Update > Check for updates.
  Keeping your build current ensures you have the latest fixes for Windows Search bugs.

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Method 2: Check the Windows Search Service

Outlook relies on the Windows Search engine. If this service isn’t running, Outlook can’t find anything.

1. Press Win + R, type services.msc, and press Enter.
2. Locate Windows Search.
3. Check the “Status.” If it’s not Running, right-click and select Start.
4. Ensure “Startup Type” is set to Automatic (Delayed Start).

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Method 3: Include Outlook in Indexing Locations

Sometimes Outlook is excluded from the list of locations the computer is allowed to “crawl.”

1. Go to File > Options > Search > Indexing Options.
2. Click Modify.
3. Ensure the checkbox for Microsoft Outlook is selected.
4. If it was already checked, uncheck it, close Outlook, reopen it, and check it again to “toggle” the setting.

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Method 4: Repair Your Outlook Data Files (.PST/.OST)

If the database file containing your emails is corrupted, the search engine will skip over the unreadable parts.

• For OST files: Close Outlook, go to C:\Users\%username%\AppData\Local\Microsoft\Outlook, and rename your .ost file to .old. Outlook will recreate a fresh file when you restart.
• For PST files: Use the Inbox Repair Tool (scanpst.exe). You can usually find this in your Office installation folder. For a walkthrough on finding this tool, check this guide from How-To Geek.

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Method 5: Use the Office Online Repair Tool

If the application files themselves are damaged, a repair is necessary.

1. Right-click the Start button and select Installed Apps.
2. Find Microsoft 365.
3. Click the three dots and select Modify.
4. Choose Online Repair. This is more effective than “Quick Repair” as it replaces all corrupted files from the cloud.

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Method 6: Adjust the Sync Slider Settings

Is Outlook not searching old emails? You might not have them downloaded to your computer.

1. Go to File > Account Settings > Account Settings.
2. Select your email and click Change.
3. Look for the Download email from the past: slider.
4. If it’s set to “1 Year,” Outlook won’t search anything older locally. Move it to All to ensure everything is indexed.

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Method 7: Disable Conflicting Add-ins

Some third-party tools (like older versions of antivirus or CRM integrations) interfere with the search bar.

1. Restart Outlook in Safe Mode (Hold Ctrl while clicking the Outlook icon).
2. Test the search. If it works, an add-in is the culprit.
3. Go to File > Options > Add-ins > Go and disable them one by one.

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Method 8: Advanced Registry Fix for Search

Disclaimer: Changing registry keys can be risky. Export a backup before proceeding.
Sometimes a registry key tells Windows to ignore Outlook indexing.

1. Press Win + R, type regedit.
2. Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search.
3. If you see a DWORD named PreventIndexingOutlook set to 1, change it to 0.
4. If the key doesn’t exist, this likely isn’t your issue.

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Method 9: Create a New Outlook Profile

If your profile is corrupted, no amount of indexing will fix it.

1. Open Control Panel and search for Mail.
2. Click Show Profiles > Add.
3. Name the profile “Test” and add your email account.
4. Set “Always use this profile” to your new one and restart Outlook.

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Method 10: Check Group Policy Settings

If you are on a work computer, your IT department might have disabled certain search features. Check with your admin or look at the Microsoft Tech Community forums to see if a recent company-wide update broke the search functionality for others in your organization.

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20 Frequently Asked Questions (FAQs)

1. Why is Outlook search results incomplete?
Usually, this means indexing is still in progress. Check the status via Search Tab > Search Tools > Indexing Status.

2. Where did the search bar go in Outlook 365?
Microsoft moved the search bar to the very top blue title bar to save space in the main ribbon.

3. Why does my Outlook search say “Something went wrong”?
This is typically a service communication error. Restarting the “Windows Search” service in services.msc usually fixes this.

4. How do I fix Outlook search on Windows 11?
Windows 11 requires the “Windows Search” feature to be enabled in Optional Features. Also, ensure your Windows 11 is updated to the latest build.

5. Does Outlook search work offline?
It only works for emails that have been downloaded locally (Check your Sync Slider).

6. Why is Outlook search not working after a Windows update?
Updates can sometimes reset indexing permissions. You may need to “Rebuild” your index after a major OS update.

7. Can I use the search bar to find attachments?
Yes, use the syntax hasattachments:yes or use the Refine tab in the search ribbon.

8. How do I clear my Outlook search history?
Click the search bar, and in the “Recent Searches” dropdown, click “Clear searches.”

9. What is the limit of search results in Outlook?
By default, Outlook limits results to 250 for speed. You can change this in File > Options > Search.

10. Why is the “Indexing Options” button greyed out?
This often happens if you don’t have Administrative privileges or if a Group Policy is blocking it.

11. Does “Repairing” Outlook delete my folders?
No. Repairs affect the program files, not your actual email data.

12. Why is my Outlook search slow?
A very large .ost file (over 50GB) can cause significant lag. Consider archiving old mail.

13. How do I search for an exact phrase?
Use quotation marks, for example: “quarterly report 2023”.

14. Why is Outlook not searching the “Deleted Items” folder?
By default, Outlook excludes Deleted Items. You can change this in File > Options > Search > “Include results from the Deleted Items folder.”

15. Can I search multiple accounts at once?
Yes. Change the dropdown next to the search bar from “Current Mailbox” to “All Outlook Items.”

16. Does Outlook search work on Mac?
Outlook for Mac uses “Spotlight” for indexing. If search fails, you must re-index your Mac’s hard drive.

17. What does “Search results may be incomplete” mean?
It means the indexer is currently busy cataloging your emails. It will disappear once finished.

18. How do I find the ScanPST tool?
It’s usually in C:\Program Files (x86)\Microsoft Office\root\Office16.

19. Why does my search work in Webmail but not the Desktop app?
Webmail uses server-side indexing (Google/Microsoft servers), whereas the desktop app uses your local PC’s indexer.

20. Will reinstalling Office fix search?
It’s a last resort, but yes, it often fixes underlying file path issues that “Repair” might miss.

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Final Thoughts

When Outlook 365 search is not working, the culprit is almost always the Windows Search Index. Start with a rebuild, ensure your sync slider is set to “All,” and keep your software updated. For further technical reading, check out the BleepingComputer technical forums for community-driven fixes to recent Windows bugs.

By following these steps, you can ensure your search is fast, accurate, and reliable. Stay productive!

Method 8: Advanced Registry