Outlook 16.23.1 not searching correctly on Mojave 10.14.4

It is still unacceptable that Microsoft and Apple doesn't solve this problem together.

I buy software, to avoid this kind of problems.

Maybe I can better use open source software, they have a faster and better support then a billion dollar company as Microsoft.

@Microsoft please solve this problem.

The same hit me from a time-machine restore to a new mac air. All of the things in various threads didn't work (in the past have always used mdimport when this occurred). Until today, now working. The two main deltas:

1. Updated to Mojave 10.14.6. Even though that didn't seem to have an immediate impact (incl. after usual of dragging ~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/ to Spotlight/Privacy, then removing - after watching for the mds task in activity monitor to 'finish', and still hours after that, searching in outlook 2016 gave no results,
2. At that point was preparing to uninstall and reinstall Office. Needed to archive a local folder in outlook (itself an 'archive' of past emails), and so set all emails in that to the same category (yellow etc), to then export this category to a .olm archive, to bring this back in (import) after the reinstall. This took a while, and I wonder if this was possibly the reason search is now working. Another thread mentions a metadata attribute on emails that's changed in Mojave (kMDItemKind is being set to "Document" in Mojave and "olk15_message" in High Sierra), and whether using a category on some email, combined with exporting (which would search all emails for that category) somehow also updated this metadata attribute (on all emails) to what Mojave needs/uses. 

Anyway, after a week of wrestling with this, search seems to be working for me, finally.

We tried many of all the tips, and none of them have worked.

Could it be related to Standard user accounts vs Admin accounts?

We did a complete uninstall of Office and reinstalled it with a local admin user account.

When we add the Exchange account in the Outlook client in the admin user, the search was working.

We gave the local standard user admin rights and configured the Exchange account in the Outlook client. Search did not work.

We switched back to the admin account, the search stopped working too.

We restarted the computer.

We were about to give up, logged in the admin account, removed the Exchange account from the admin account, switched the other user back to the standard user rights, logged out of admin, we logged in the standard user, tried search in Outlook one last time and was surprised that search was working!

Apparently, Outlook uses Spotlight for indexing and search functions. So even though the search is inside Outlook and it looks like Outlook is doing the searching, Outlook is really using Spotlight. Spotlight is supposed to index all readable content on your Mac.

For some reason, mail in Outlook stops getting indexed by Spotlight, and thus stops appearing in search results in Outlook (because it's not in the Spotlight index).

Deleting the mail account in Outlook, then re-adding and waiting for the mail to get indexed is the only thing that has worked for me. Unfortunately, it doesn't work permanently; after a while, some mail doesn't get indexed again and isn't searchable. But it worked for me for a while as a temp hack fix.

I tried all the solutions suggested in the thread and nothing is working for me. 

I tried adding the Profile folder to the Privacy Tab and remove it, but nothing changed after that. How is Spotlight related to the search functionality within the Outlook? What's not working for me is the search inside the outlook, I never use spotlight to search for emails