Hello BGPK,
Welcome to the Microsoft Community.
I understand that the search function in Legacy Outlook on your Mac is not working properly.
Try manually adding the Outlook profile to the Spotlight index using the mdimport command.
Please replace <user_name>
and <profile_name>
with the actual names of your folders. Note that you should avoid including special characters in the profile name, as this may cause the indexing to fail.
mdimport "/Users/<user_name>/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/<profile_name>"
If it still doesn't work, you can try rebuilding the index again after upgrading your macOS version. Sometimes, a version upgrade can resolve certain issues.
Please feel free to let me know if you have any further updates, thanks.
Best Regards,
Zachary.W - MSFT | Microsoft Community Support Specialist