After installing update KB5008212, Outlook emails are missing from the Outlook search results.
This update was released on January 5, 2022 and as of January 13, 2022 we have witnessed it is still being installed via the Windows Update Service.
The status of when this update might be pulled from the Microsoft update pool is unknown.
We have learned you can disable the Windows Desktop Search which will cause Outlook to use it’s built-in search versus the Windows Search service.
The built-in search will display a message stating it is not using the Windows Search service and that performance will be impacted.
You can follow these steps below to disable Windows Desktop Search Service for Outlook.
Important: The following steps show you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly.
Please make sure that you follow these steps carefully.
For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, go to How to back up and restore the registry in Windows.
Right-click Start, and then select Run. In the Open: box type regedit, and then click OK.
Find this subkey in the registry and then click it:
Click Edit > New > Key and name the new key Windows Search.
Select the new Windows Search key.
Click Edit > New > DWORD Value.
Type PreventIndexingOutlook for the name of the DWORD, and then press Enter.
Right-click PreventIndexingOutlook, and then click Modify.
In the Value data box, type 1 to enable the registry entry, and then click OK.
Exit Registry Editor, and then restart Outlook.