The issue is that Office 2016 limits the search results to 75 items

It seems on some setups Office 2016 limits the search items display to 75###[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Search]“SearchResultsCap”=dword:00000000“DisableServerAssistedSearch”=dword:00000001###SearchResultsCap overrides how many items are viewable in your search results. 0 is all.DisableServerAssistedSearch […]