Hello
Thank you for posting in Microsoft Community forum!
Here are a few suggestions that might help resolve the problem:
Rebuild the Search Index:
Open Outlook and go to File > Options > Search.
Click on Indexing Options and then Advanced.
Under the Index Settings tab, click Rebuild. This will rebuild the search index and might resolve the issue.
Check Windows Search Service:
Ensure that the Windows Search service is running. You can do this by opening Services.msc, finding Windows Search, and making sure it is set to Automatic and is running.
Exclude Outlook from Windows Indexing:
Temporarily exclude Outlook from items that are scanned by the Windows Indexing Service. In Outlook, go to File > Options > Search > Indexing Options, and uncheck Outlook from the list.
Update Outlook and Windows:
Make sure both Outlook and Windows Server are fully updated. Sometimes, updates contain fixes for known issues.
Run System File Checker:
Open Command Prompt as an administrator and run sfc /scannow. This will check for and repair any corrupted system files that might be affecting the search functionality.
Check Group Policy Settings:
Ensure that there are no Group Policy settings that might be affecting the search functionality. Sometimes, policies can inadvertently disable or restrict search features.
If these steps don't resolve the issue, it might be helpful to look into more specific logs or errors that could provide further insight.
Best Regards,
Wesley Li