How do I rebuild the search index in Microsoft Outlook?
If Outlook is not searching all of your email correctly, you can rebuild the Outlook search index to fix this:
Click on File then Options
Select Search on the left then click Indexing Options
Click Advanced
Click the Rebuild button
This will cause Outlook to rebuild its entire search index. This can take a long time to complete but you can continue to use Outlook and it will do this in the background.