

Additionally, when you search for mail items by using the Mac OS native Spotlight Search, your search is unsuccessful. In Microsoft Outlook 2016 for Mac, you receive a "No Results" message when you try to search for an email message or apply a filter to a folder, and task items are not displayed in the Tasks folder. For your issue, I have tried to disable windows search and search in online mode on my Outlook 2016 for testing, and found it indeed couldn't work normally, which is same with your issue. Search from Outllok by using 'normal' Search box: search is not working and I get mixed results. I search keywords in the last sent email - and the search comes back with 'no results' when it is clearly there, in the last sent email. I cannot find any emails with a search term.

This Microsoft support article has more detailed information on search issues and troubleshooting tips - Hi AndreaGaviraghi-6588, Welcome to our forum. Recently updated to Office 2016 and found that instant search is not working. Recently updated to Office 2016 and found that instant search is not working. In the Troubleshooting section, select Rebuild.In the "Change the Outlook stores indexed by Windows Search", click Indexing Options.In case this issue was caused by software conflicts, please try performing a clean boot in Windows to check the result. This helps eliminate whether the problem lies on any third party add-ins. Modifying your query may resolve this problem" or "Outlook cannot perform your search." Please exit Outlook, press Win key + R to open the Run command, type outlook.exe /safe and then press Enter. You may also receive a message "Instant search encountered a problem while trying to display search results. If your search function isn't finding any of your messages or only recent messages in the last two weeks, you may need to rebuild the search index.
