Search Results can’t be moved or Categorized and Categories column isn’t shown

I heavily rely on the Search feature within Outlook to efficiently triage my emails. However, something appears to have been changed to how Search works. For instance;

  • When I move messages from my Search results to a different folder, this isn’t directly reflected in the Search results anymore (when sorted by folder).
  • Mailbox wide searches are always sorted by date instead of by folder.
  • The Categories column isn’t shown even though it is added to the View.
  • Categories are shown when the message is opened in the Reading Pane but I can’t remove them.

How I can I return Outlook’s Search behavior back to the way it was before?

Exchange Based Search buttonWhen you are using Outlook 2016 with an Exchange account, Outlook will leverage the Exchange Search Index instead of the local Windows Search Index for more consistent search results across various Outlook configurations and Outlook (Web) Mail apps.

This however does affect some of Outlook’s old search results behavior and feature availability as well.

You can set the DisableServerAssistedSearch Registry value to return the previous search behavior that relies on the local Windows Search Index.

Background information

More Info buttonBy using the Exchange Search Index instead of the local Windows Search Index, you’ll get the same search results no matter how you are working with a mailbox.

For instance, with the previous behavior, you would get different search results when…;

  • … Cached Exchange Mode is enabled.
  • … Cached Exchange Mode is disabled.
  • … only a part of your mailbox is cached (Sync Slider feature).
  • … searching the mailbox as a delegate.
  • … searching the mailbox via Outlook on the Web or Outlook Web App (OWA).
  • … searching the mailbox via a mobile client or Outlook app.

Unfortunately, this also means that some Outlook features, like Categorizing, aren’t fully available and changes aren’t directly reflected in the Search results anymore.

This is because the Search results are online and your changes are being made in the local cache of Outlook which need to be synched back to the server first (this occurs within 60 seconds). In order to see your changes reflected in the Search results, you’ll need to repeat your Search query.

Aside from the improved Search results consistency, another reason to prefer the Exchange Search Index over the local Windows Search Index is because the Windows Search Index relatively often became corrupt or was outdated when it comes to Outlook and that it can’t index items which aren’t cached by Outlook (Sync Slider feature) and the user had to manually repeat the query against Exchange (Hybrid Search via the More link are the bottom of the Search results).

Note: When the Exchange server isn’t available or when working offline, Outlook will automatically fall back to the Windows Search Index to display the Search results.

Create the DisableServerAssistedSearch Registry value

Regedit buttonTo force Outlook to use the local Windows Search Index instead of sending the Search query to Exchange, you must set the DisableServerAssistedSearch Registry value to 1.

Key: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Options\Search
Value name: DisableServerAssistedSearch
Value type: REG_DWORD
Value: 1

As this value probably doesn’t exist in your Registry yet, you’ll need to create it first. If you are not really into editing the Registry yourself, you can also download this zip file. It contains a file to add the Registry value and also a file to reset the behavior and re-enable Exchange Based searching again.