Outlook 16.23.1 not searching correctly on Mojave 10.14.4

I interacted with MS's dedicated Outlook for Mac support team via the Contact Support feature on the Help menu in Outlook. I was told to do the following, 

Quit Outlook completely and then open Terminal on the Mac and then copy and paste the command

sudo mdutil -E / 

It would prompt for your Mac Password please enter it and wait for it to complete and then give it some time and then re-launch Outlook and check if that helps. If you still face issues. 

Quit Outlook completely by click on Outlook Menu > Quit Outlook and then try the steps 

1. Choose Apple menu > System Preferences, then click Spotlight.

2. Click the Privacy tab.

3. In Finder:

a. On the Go menu click Go to Folder...

b. Copy and paste the following location into the "Go to the folder:" dialog box and click Go:

~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/

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.

See the following article from Apple to learn more: https://support.apple.com/en-us/HT201716

This appeared to work - messages were appearing in search results. But unfortunately, the fix was short-lived. Newer mail is still not appearing in search results. (I can be looking at a message just received in my inbox, search for it, and get no results). So there's still a problem. But at least I temporarily have some kind of search capability. 

I have posted this back to the Outlook Support team and will update this thread if they respond with helpful suggestions.

Hi yobelow,

Thanks for posting back and sharing the useful information in our community. If you have any further updates on this problem, welcome to post back again.

Thanks,

Huni

This is still happening to users in our org and it is completely unacceptable.  Is there any word on if this is specifically being addressed?  Also has anyone else with the issue nail down the exact scenario in which this issue pops up ie Outlook build + MacOS version being factors?

I'm curious to see if this is happening to anyone running the 16.23 build of Outlook on older version of macOS 10.12 or 10.13

This same problem happened to me periodically with a range of different Outlook builds and MacOS versions. I could never definitively nail down why it happened, but my suspicion was that it happened when Outlook wasn't closed gracefully.

The solution was always to run the following in Terminal:

mdimport -g ‘/Applications/Microsoft Outlook.app/Contents/Library/Spotlight/Microsoft Outlook Spotlight Importer.mdimporter’ -d1 ‘/Users/USERNAME/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/Main Profile’

... where USERNAME was the home directory name on my Mac. This took a while to run, but always resolved the issue. 

But mdimport -g is not supported under MacOS 10.14.4 (Mojave), so I no longer have a fix. I'd recommend to everyone not to upgrade to Mojave until a fix is available. When using earlier MacOS versions, the problem is fixable using the above-mentioned process. I cannot say definitively which versions of Outlook it worked with, but it worked with every version I ever tried it with.

Thanks yobelow.  It's a tricky thing to try to fix for our users because it takes a pretty specific search query to actually reveal that there is an issue but we are trying to nail down what specific circumstances cause this issue to occur.

Also, why hasn't Microsoft Support addressed the issue with the blank Outlook Search Repair tool window in Mojave?  Seems like something they would be aware of and fixing.  Mojave has been out since September 2018