If the 68 results shown are not what you need, you can expand the search:
Microsoft introduced these caps to prevent long wait times while searching large mailboxes. Search results for office 2016 (68)
If you are seeing a specific number like "(68)" in your search header, it indicates that Outlook has found that many matches in your local index or initial server query . Why Results Are Limited If the 68 results shown are not what
In Outlook 2016 and later, the application first submits a query to the Exchange server before rendering results . How to View More Results Search results for office 2016 (68)