Outlook 16.23.1 not searching correctly on Mojave 10.14.4

I just updated to 10.14.5 but unfortunately the problem persist.

The weird part is that after doing the re-indexing now I'm able to search through the spotlight, but not within the outlook 

My understanding is that the upgrade to 10.14.5 (supposedly) fixes the problem going forward. But if you already have mail that doesn't show up in search results, it may not fix that legacy issue. (I can't swear to this, but I think it's right).

Deleting and re-adding the mail account seemed to make all the mail in that account searchable. So did selecting a folder, right-clicking, and selecting Repair folder. (The former will reindex the entire account whereas the latter reindexes that single folder (by deleting and downloading fresh from the server).

Perhaps the combination of upgrading to 10.14.5 for ongoing and deleting/adding account or folder for historical is the answer.

ok it worked for a few seconds and then it stopped. It was actually working for new emails, and then I removed the account, added it again, wait until the indexing finished and it's not working any more

FYI, This problem seems to be resolved for my after upgrading to MacOS 10.14.5 and reindexing the outlook profile (see below steps).

Thank you for this post. I had a similar issue but not caused during the update but after a Time Machine installation on a new Mac. Outlook did not search. I tried everything from this post and other posts as well. Only solution that managed to work for me was to delete Outlook App, delete Outlook containers and profiles. Just like written in here but only the Outlook part: https://support.office.com/en-us/article/uninstall-office-for-mac-eefa1199-5b58-43af-8a3d-b73dc1a8cae3 Afterwards I reinstalled Outlook and now it works just fine. It was a long process but I couldn't manage in any other way.

I tried all of the steps mentioned here, and also some steps on other sites. Nothing worked.

So, as a last ditch effort, I dragged the "MainProfile" folder out of the "Outlook 15 Profiles" and put it on the desktop. 

Then waited about 2 seconds, then dragged it back into the "Outlook 15 Profiles" folder.

Immediately fixed the problem.

Hope this helps.

yobelow's solution looks interesting, I may try that next time to see what just sudo mdutil -E /does

Before Mojave, I used to use the solution described here "Outlook for Mac search returns "No Results," and task items are not displayed"

I am running macOS Mojave version 10.14.5

of course what the OP and most of us here used to do if the re-indexing failed was go to terminal and run a command such as this...

mdimport -g "/Applications/Microsoft Outlook.app/Contents/Library/Spotlight/Microsoft Outlook Spotlight Importer.mdimporter" -d1 "/Users/<user_name>/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/<my_profile_name>"

but the option -g, as far as I can tell, was to specify a path and use Microsoft's custom spotlight importer ( the notes say "-g" is the default path of the Outlook installation) and the old mdimport man page says, (-g plugin  Import files using the listed plugin, rather than the system installed plugins. )which is not supported in Mojave. I admit here my understanding is really fuzzy so I am sure someone else could point me to a man page.

I ran the steps he re-posts that have been the steps to "re-index"

REINDEXING STEPS

4. Drag the ‘Main Profile’ folder to the Privacy tab. Once added, remove the folder, and Spotlight will re-index the folder. Note: You must perform this step for any additional profile folders you may have. The status of the re-indexing is not shown anywhere. so you need to wait for some time and check the result.

However these steps only work if your existing System Spotlight Index isn't corrupt.

In my case, this didn't work the first time around. The solution was to do a system-wide re-index of the Spotlight database.  Some googling turned up a response by "Tim Hardwick" of macrumors and commenter "macdaddy44" say that can be accomplished do the following (I have not tested this)

Version 1 (minimal)Type command

"sudo rm -R /.Spotlight-V100"

Then type the command (-i (on|off) Turn indexing on or off)

"sudo mdutil -i on /"

Then type the command (-E Erase and rebuild index.)

"sudo mdutil -E /" 

Version 2 (more exhaustive)

Type the commands...

"mdutil -i off /"

"sudo rm -rf /.Spotlight-V100"

"sudo rm -rf /.Spotlight-V200"

"mdutil -i on /"

"mdutil -E /"

What I did is Version 3...

Version 3 (Using a third-party utility)

This appears to also do what the above, but because I didn't check the files it is modifying, so it's a mystery of the black box of 3rd party software because I used a utility to do it. I did this using Titanium Software's free Onyx utility, which is available for all recent versions of macOS (use the version for your OS).

I wasn't sure what was too much to select so I unchecked everything and only selected "Spotlight index" and "Mail's mailboxes" and radio button for "Delete the existing index"

After I did that, it still wasn't fixed I had to re-apply the REINDEXING STEPS listed above to get repair the Outlook 2016 files.

There are other problems that exist and there may be options to do this all from the command line rather than hokey pokey going to through the gui. It appears that duplicate installs of Outlook spotlight instances can also be a source of problems and Spotlight can get stuck on certain folders (which I think is part of why we re-index those folders using the gui but I think this is also possible from the commandline I'm still working that out.)

List existing importers and check for duplicates

/usr/bin/mdimport -L

Ok, I'll stop editing this post.

References

[1] How to get Outlook email indexed by Spotlight after reinstalling Office 2011? - Ask Different
[2] Reindex Spotlight from the Command Line in Mac OS X
[3] Outlook for Mac search returns “No Results,” and task items are not displayed
[4] Titanium Software | Operating system utilities for Mac - OnyX
[5] Outlook 16.23.1 not searching correctly on Mojave 10.14.4 - Microsoft Community
[6] How to Rebuild the Spotlight Index on Your Mac - MacRumors
[7] How To Fix Spotlight Forever Indexing issue on Mac OS X | Technobezz
[8] Outlook 2016 for mac search is not working. Have tried reindexing - Microsoft Community

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!