Mail search

In the past, when I entered a search term in mail search, individual emails would be pulled up in real time containing the search term in the content of the emails. It was very useful. Now though, there are no real time results. Also, the results are categorised under the headings 'subject' and 'people', and you can't see the content of the various emails pulled up unless you click on them. As lots of emails often have the same subject headings, the results are useless. If you click on the search term itself as an 'item', the results come up extremely slowly and seem very random. In short, the search is now functionally extremely poor whereas it used to be invaluable. Spotlight search is not helpful in resolving this as I want to be able to search within Mail, just like before. Is this a malfunction with my search or is this a deliberate change by Apple?