Google Drive documents results used to be shown below Gmail search results.  That option was a labs enabled tool where when you searched Gmail you would see matching Google Drive documents below the email results.  Is there a way to re-enable that? It appears Google has disabled that function.This is a Google Apps for Business account.Apps Search does not appear under Labs in Settings for any users even though it is enabled in Domain Admin > Apps > Google Apps > Settings for Gmail > Labs
Re-enable Google Drive results for Gmail searches in Google Apps for Business
gmail;google;google drive