I have same issue on my new MacBook Pro that has recently updated to macOS Monterey 12.1 Outlook Support was very fast to help me by suggesting to add my Outlook Profile to the Privacy tab of the Spotlight Settings, which will exclude any information within Outlook from being indexed by Spotlight. The next step is to delete the very same profile from the Privacy tab, which immediately kicks off the process of re-indexing everything under the Outlook profile. You can check this by going into Activity Monitor where you will probably see processeses named 'mds' or 'mds_stores' running. Usually a lot of CPU is used when a fresh re-index kicks off. If the above doesn't work, Outlook Support suggest dragging the Mac HD into the Privacy tab (similarly as described above), and then delete it, which will re-index the entire Mac HD including the emails stored in the same profile (above) within Outlook. In the past, I have found that one of these 2 approaches work; however, in this case, no. So I still cannot search for anything in my emails in Outlook, which makes the app almost useless as I need to search my emails and calendars continually throughout the day for crucial and time-sensitive information. Does anyone know if a software upgrade is acknowledged and is on its way from Microsoft or Apple?