How to force Indexing of PST File on Legacy Outlook for Mac

Question

How to force Indexing of PST File on Legacy Outlook for Mac

B. Parker 0

I'm running the latest Mac OS (Tahoe) with an updated version of Outlook for Mac. I'm using the Legacy version because I need to be able to access PST files which I've made of various older email accounts and the newer version of Outlook for Mac does not yet support PST files being imported.

I have the PST file stored locally on the Mac HD. The PST file loaded into Legacy Outlook and I can access all the emails, etc.

The only issue that's appeared is that Outlook will not index the emails on the PST file and therefore searching for content is not practical.

Thoughts?

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2 answers

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Answer 1

Ryan-N 12,580 Microsoft External Staff Moderator

Hi @B. Parker,

Welcome to the Microsoft Q&A forum.

I would like to provide you with the following information.

Please follow the steps below:

Rebuild macOS Spotlight

Via System Settings (no Terminal):

Open Apple menu > Spotlight > Search Privacy.
Add Macintosh HD (or the Outlook data folder) to the Privacy list, then remove it to trigger re‑indexing.
You can check progress by clicking the Spotlight icon and starting a search—macOS will show an indexing bar.

Via Terminal (quick and thorough):

Rebuild Spotlight index for the boot volume
- sudo mdutil -E /
If your Mac uses APFS, rebuild the Data volume as well
- sudosudo mdutil -E /System/Volumes/Data
(Optional) Rebuild all mounted volumes

During re‑indexing, search may temporarily return limited results.

Validate Outlook’s Spotlight Importer

Legacy Outlook integrates with Spotlight via Microsoft Outlook Spotlight Importer.
- mdimport -L
If you see more than one entry called Microsoft Outlook Spotlight Importer.mdimporter, keep the Outlook app you use, remove any duplicate Outlook app from Applications, Empty Trash, then restart the Mac.

Note: On newer macOS versions, some older mdimport flags are deprecated. If you see such messages, the Spotlight rebuild in step 1 (mdutil) is sufficient.

Confirm profile location and name

Standard Legacy Outlook profile path:
- ~/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/
Open Outlook Profile Manager:
- Finder > Applications > Microsoft Outlook > Show Package Contents > Contents > SharedSupport > Outlook Profile Manager.
Ensure the Profile name contains no special characters (e.g., “/”). If it does, rename the profile folder accordingly.

(Optional) Refresh cache per folder

In Legacy Outlook, right‑click a mail folder > Properties > Empty Cache. Outlook will reload that folder’s content from the server.

Validate search after rebuild

Try a few queries:
- subject:"invoice"
- from:Contoso
- hasattachment:yes

I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this.

Thank you for your patience and your understanding. If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.

I look forward to continuing the conversation.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

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B. Parker 0 Reputation points

2026-03-28T15:56:28.1733333+00:00

Thank you Ryan-N,

I did all the suggestions provided by the Q&A Assist (above) and it did not solve the issue. I even removed Office from my Mac and reinstalled Outlook. After leaving the Mac running for more than 12 hours, it still only returns 59 items for a search, which if I perform on my Win 11 Pro PC version of Outlook (on the exact same PST file) returns 112 items.

I'll start attempting your solutions and keep you posted.
Ryan-N 12,580 Reputation points Microsoft External Staff Moderator

2026-03-28T15:59:34.4533333+00:00

Hi @B. Parker,

Thank you for your response. If there are any updates regarding this issue, please feel free to share them with me. I will be happy to assist you.
B. Parker 0 Reputation points

2026-03-28T16:16:56.7533333+00:00

Just to be clear, when I'm performing the search for items, I am using the Search function within Outlook, not Spotlight. I don't know if that is solved by your suggestions about resetting Spotlight.
Ryan-N 12,580 Reputation points Microsoft External Staff Moderator

2026-03-28T16:49:38.8333333+00:00
Hi @B. Parker,

Thank you for your response. I completely understand your concern.

Unlike Outlook on Windows (which has its own built‑in search index), Outlook Legacy on Mac does not maintain an independent search database. Instead, it relies entirely on macOS Spotlight indexing to return search results.

When you enter a keyword in the Search box in Outlook, Outlook is actually sending a background search query to Spotlight.

If Spotlight has not yet been able to “read” the contents of the .pst file, Outlook may return no results or only partial results.

On macOS (especially newer versions such as Tahoe), .pst files are not treated by default as indexable text files. Only after Outlook opens the file and registers it with the system does Spotlight begin scanning and indexing its contents.

If the indexing process becomes stuck, running the command sudo mdutil -E / in Terminal (as I previously guided) will force Spotlight to rebuild the entire index, including data related to Outlook Legacy.
B. Parker 0 Reputation points

2026-03-28T17:20:04.2333333+00:00

Preformed the Spotlight Rebuild with the first suggestion - Via System Settings (no Terminal) and after rebooting and waiting an hour - it's made the situation worse. No incidences of the item being searched for appear in Outlook. Going to the Terminal Reset suggestion.
Ryan-N 12,580 Reputation points Microsoft External Staff Moderator

2026-03-28T17:35:07.19+00:00

Hi @B. Parker,

Thank you for your response. I truly appreciate that you have carried out the steps I shared.

If the steps above do not resolve the issue, I recommend that you create a support ticket to contact Microsoft Technical Support directly.

Once the system receives the ticket and assigns it to a suitable agent, the support engineer will proactively contact you and may initiate a remote session to thoroughly review and resolve this issue for you.

Note: The steps below require tenant administrator (Global Admin) permissions. If you do not have administrator access, please contact your organization’s IT department for assistance.

Step 1: Go to admin.microsoft.com

Step 2: Select Help & Support

Step 3: Enter the title: Need support for Outlook legacy

Step 4: Select Contact Support

Step 5: Choose your preferred contact method

If you have any questions or need further assistance, please feel free to share them in the comments on this post so I can continue to support you.

I look forward to continuing the conversation.
B. Parker 0 Reputation points

2026-03-29T01:50:37.21+00:00

Thank you Ryan,

I completed the Terminal commands (sudo mdutil -E / with the following variance - see below.

I was prompted for a Password, which I assume would be the password for the Administrator Account, however it would not accept it. (Maybe that's due to the fact that the Admin Acct. password has special characters in it?)

So, I logged into the Admin Account and entered the sudo command on the Terminal in the Admin Account directly. The command was accepted. (I don't know if that means that it'll prompt a re-indexing in the Standard User Account(s), but I hope so.)

I rebooted the system.

Now, after several hours to allow Spotlight to comb through the PST file, it only returns with nine records with the searched keyword, whilst Outlook on a PC (using a copy of the same PST file) returns forty-six.

I'm curious, for Spotlight to search the PST - does Outlook need to be running and open on the desktop, or will the search be performed in the background regardless?
Ryan-N 12,580 Reputation points Microsoft External Staff Moderator

2026-03-31T22:42:50.72+00:00

Hi @B. Parker,

Thank you for your response.

Based on how it works, Outlook does not need to be open or running in the background for Spotlight to search emails that have already been synced or imported. Spotlight uses a dedicated filter (Spotlight Importer) to index Outlook data even when the application is not running.

Previously, the information I provided was intended to rebuild the Spotlight index and verify how Outlook is integrated with Spotlight.

Since the result is still not as expected, I commented to recommend that you contact Microsoft technical support for further investigation. They will perform a remote session to review the settings on your device and check whether any configuration or permission is preventing Spotlight from searching information properly. (These steps do not access or affect your personal data.)

Answer 2

Legacy Outlook for Mac relies on macOS Spotlight for search, so PST content must be fully indexed by Spotlight. Use these steps to force or repair indexing for the profile that contains the imported PST:

Run the OutlookSearchRepair utility
- Follow the guidance in the search troubleshooting article to run the OutlookSearchRepair tool for Outlook for Mac. This repairs the Spotlight integration used by Outlook search.
Allow time for indexing after importing the PST
- After importing a PST or OLM file, Outlook may show "No Results" until Spotlight finishes indexing the new data. Leave Outlook open and the Mac powered on for a while, then try the search again.
Ensure the Outlook profile name is Spotlight‑friendly
- If the profile name contains special characters (for example, a slash /), Spotlight indexing can fail.
- To check the profile name:
  1. In Finder, select Go > Applications.
  2. Right‑click Microsoft Outlook > Show Package Contents.
  3. Open Contents > SharedSupport > Outlook Profile Manager and review the profile name.
- If needed, rename the profile folder to remove special characters:
  1. Open /Users/<Username>/Library/Group Containers/UBF8T346G9.Office/Outlook/Outlook 15 Profiles/.
  2. Rename the profile folder and remove any special characters.
Force a reindex of the Outlook database via Terminal
- Use Terminal to trigger Spotlight to reindex the Outlook profile that contains the PST:
- Run (substitute the actual user name and profile name):
```
     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>"
```
- Wait for reindexing to complete, then quit and restart Outlook.

If search still does not return results after these steps and sufficient time for indexing, the documented next step is to completely remove Office for Mac and reinstall it, then re‑import the PST and allow indexing to complete again.

References:

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How to force Indexing of PST File on Legacy Outlook for Mac

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