Outlook 2024 (POP/PST): Search does not index HTML email bodies (IFilter issue)

Question

Outlook 2024 (POP/PST): Search does not index HTML email bodies (IFilter issue)

bernard Andri 15

Hello,

I am facing a persistent search issue in Outlook 2024 (using POP accounts with .pst data files). The search function only returns results if the keyword appears in the Subject line or in the name of an attachment. Words inside the email body are ignored, unless the message is formatted as Plain Text (HTML-formatted bodies are not indexed).

Here is what I have already checked and tested:

Indexing Status: Windows Search indexing completed successfully, and Outlook reports 0 items remaining to be indexed.
Indexing Locations & File Types:
- Microsoft Outlook is correctly listed under Included Locations.
  - Under Advanced Options > File Types, .pst is set to "Index Properties and File Contents".
    - Observation: In Indexing Options > Advanced > File Types, the .pst extension shows "Plain Text Filter", whereas .msg shows "Office Outlook MSG IFilter".
    1. Registry Tweaks: I spent significant time attempting registry modifications to force Windows Search to use the correct IFilter for HTML parsing inside PST files, but without success.
    2. Safe Mode: Search works as expected when running Outlook in Safe Mode (since Outlook falls back to its built-in legacy search engine), but it is naturally very slow as it rescans on every query.
    3. New Profile & Clean PST: I created a fresh Outlook profile with a minimal PST file containing only a few test messages. The problem persists even on a clean setup.

It appears Windows Search is failing to load or assign the proper IFilter to handle HTML-formatted message bodies inside PST containers in Outlook 2024. Any insights or registry/DLL fixes to restore proper HTML body indexing would be greatly appreciated.

Thank you!

Zahid Barrera Ramirez 465 Reputation points

2026-09-06T21:12:53.53+00:00

Your Safe Mode test is probably the most important clue here.

If body searches work in Safe Mode but fail with Windows Search enabled, and the same behavior occurs with a new Outlook profile and a clean PST, I would stop troubleshooting the PST/profile itself and focus on the Windows Search/Office filter registration.

One thing stands out: seeing “Plain Text Filter” associated with .pst does not look right for Outlook content indexing. PST is a container, and Outlook/Windows Search should expose the message properties and body content through the appropriate Outlook search components rather than treating the PST as a plain-text file.

Before forcing an IFilter through registry changes, I would check:

• Whether the Microsoft Office/Outlook search filter components are correctly registered. • Whether Office and Windows architecture match (x64/x86). • Whether another application has modified the PersistentHandler/IFilter associations. • The Windows Search event logs for filter-host or protocol-handler errors while indexing the test PST. • Whether an Online Repair of Office restores the original search/filter registrations.

I would be particularly careful about manually assigning the MSG IFilter directly to .pst. A PST is not simply a collection of MSG files, so forcing that association could create additional indexing problems.

Given that you reproduced this with a clean profile/PST, I would also test the same PST on another Outlook 2024 installation. If HTML body content indexes correctly there, you have strong evidence that the issue is with the local Windows Search/Office integration rather than Outlook data.

At this point, ProcMon against SearchFilterHost.exe/SearchProtocolHost.exe while indexing the small test PST could also tell you which filter DLLs and registry registrations Windows Search is actually loading.

Your Safe Mode result strongly suggests the messages themselves are searchable — it is the indexed search path that is failing.
Hornblower409 18,510 Reputation points

2026-09-08T00:09:01.6466667+00:00
@bernard Andri said

Search works as expected when running Outlook in Safe Mode

Since Safe Mode's primary impact is to disable all Add-ins, it might be work trying another test:

Start Outlook normally.

File → Options → Add-ins.

Manage COM Add-ins → Go.

Take a screen shot of the dialog, or make notes, so you know which Add-Ins are normally enabled.

Disable everything by unchecking it.

Restart Outlook normally.

Do your search test.
Zahid Barrera Ramirez 465 Reputation points

2026-09-08T01:05:11.89+00:00

@Hornblower409 Good point — I agree this is an important test before going deeper into the Windows Search/IFilter path.

Safe Mode disables COM add-ins and other Outlook extensions, so the fact that search works there does not by itself prove that Outlook is bypassing Windows Search.

I would disable all COM add-ins as you suggested, restart Outlook normally, and repeat the HTML-body search test.

If the issue disappears, I would then re-enable the add-ins one at a time to identify the component interfering with search.

If the issue remains with all COM add-ins disabled, that would make the Windows Search/indexing path more interesting again, especially given that:

the issue reproduces with a new profile and clean PST,

indexing reports 0 items remaining,

Plain Text messages are searchable by body,

HTML message bodies are not,

and Microsoft expects the Outlook MSG IFilter to be correctly registered for Outlook content indexing.

At that point I would compare the filter/protocol-handler activity between normal and Safe Mode, potentially using ProcMon against SearchFilterHost.exe and SearchProtocolHost.exe.

Thanks for pointing this out — disabling the add-ins separately is definitely a cleaner isolation step before assuming an IFilter problem.
bernard Andri 15 Reputation points

2026-09-08T18:15:06.0166667+00:00

I’d already tried disabling all COM add-ins, but the problem persists
bernard Andri 15 Reputation points

2026-09-08T18:19:58.3566667+00:00

I should point out that I’ve just changed my computer. On the old one, which ran Windows 11 but had Office 2019, the search function worked. On the new computer (still an HP EliteBook), I’ve installed Office 2024. Do you think it would be worth trying to install Office 2019 instead of Office 2024 on my new laptop?
Zahid Barrera Ramirez 465 Reputation points

2026-09-08T18:24:53.6933333+00:00
@bernard Andri Yes, that comparison is very useful, but I would not replace Office 2024 with Office 2019 just yet.

The fact that the same type of POP/PST configuration worked correctly on Windows 11 with Outlook 2019, while the new Windows 11 + Outlook 2024 installation does not index HTML message bodies, makes the Outlook/Office version or its Windows Search integration a much stronger suspect.

Before downgrading, I would complete the COM Add-ins test Bernard suggested earlier:

Start Outlook 2024 normally.

Disable all COM Add-ins.

Restart Outlook normally.

Test a search for a word that exists only inside the HTML body of a message.

If the problem remains, I would then consider Office 2019 a very useful diagnostic test — not necessarily the permanent solution.

If you still have access to the old computer, an even better comparison would be to check the Windows Search/File Types configuration on both machines, particularly the Outlook-related filter registrations. That could show us whether Office 2019 and Office 2024 registered different search components.

If Office 2019 indexes the same test PST correctly on the new computer while Office 2024 does not, that would be very strong evidence that we are dealing with an Office 2024/Windows Search integration issue rather than corrupted PST data, the Outlook profile, or Windows itself.

So yes, testing Office 2019 could be worthwhile — but I would use it as a controlled troubleshooting step after testing Outlook 2024 with all COM Add-ins disabled.

Also, before changing Office versions, I would make sure you have a backup of the PST files and your Office 2019 installation/license available.

If this answer helped, please consider marking it as helpful. It helps other users experiencing the same issue find the troubleshooting path more easily.
Hornblower409 18,510 Reputation points

2026-09-08T18:57:56.48+00:00

@bernard Andri said

Do you think it would be worth trying to install Office 2019 instead of Office 2024 on my new laptop?

Before you go down that path, I would suggest that you bring in Microsoft Support. They can examine your setup and pull diagnostic logs from Outlook and Windows Indexer.

For Classic Outlook In-App Chat Support, do Help -> Contact Support
Marek Majewski 40 Reputation points

2026-09-24T09:06:13.9466667+00:00

I can confirm the same issue and have performed fairly extensive troubleshooting.

The problem has been reproduced on two different new hardware platforms:

Dell Pro Premium Lenovo ThinkPad X1 Carbon Gen 14

In both cases, Classic Outlook indexes and searches:

subject sender plain-text email body

but does not index the body of HTML-formatted messages.

I have tested:

Office 2024 Microsoft 365 Apps 64-bit Microsoft 365 Version 2608, build 16.0.20326.20132 Microsoft 365 Version 2508, build 16.0.19127.20264 after rollback clean Windows 11 installation no third-party antivirus no BitLocker no Dell/Lenovo OEM applications new Outlook profile new Windows user profile multiple index rebuilds IMAP and POP accounts

The same behavior occurs on both new hardware platforms.

I also performed additional diagnostics using MFCMAPI and direct Windows Search queries.

For an affected HTML email, MFCMAPI shows:

PR_HTML present PR_NATIVE_BODY_INFO = 3 PR_BODY_W present

PR_BODY_W contains the complete readable text of the HTML message.

The email itself is present in the Windows Search index as a mapi16:// item and its subject/sender are indexed correctly.

However, when querying Windows Search directly for a unique word that exists only in the HTML body, using:

SELECT System.ItemName,System.ItemUrl FROM SystemIndex WHERE CONTAINS(System.Search.Contents, 'unique_html_body_term')

the result is:

Rows.Count = 0

At the same time, if the same HTML email is saved as a .msg file into an indexed Windows folder, Windows Search successfully indexes and finds text from the HTML body.

This strongly suggests that the issue is not the MSG IFilter itself, but rather the path used when Outlook messages are indexed through the MAPI16 Search Protocol Handler.

In other words:

Outlook HTML message PR_HTML -> OK PR_BODY_W -> OK

MAPI16 Search Protocol Handler Subject -> indexed Sender -> indexed Plain text -> indexed HTML body -> NOT indexed

I have also tested disabling HVCI / Memory Integrity and VBS security services. This did not change the behavior.

Interestingly, this problem seems to be associated with newer hardware platforms. An older ThinkPad previously used with the same Outlook/Windows environment did not exhibit this issue.

I have already submitted this to Microsoft Support / Feedback Hub. If anyone from Microsoft is monitoring this thread, it would be useful to have this escalated to the Windows Search / Outlook MAPI indexing engineering team, as the issue appears to occur specifically when HTML body content is passed from the Outlook message store through MAPI16 into System.Search.Contents.

The fact that the same issue is reproducible on both a Dell Pro Premium and a Lenovo ThinkPad X1 Carbon Gen 14, while an older ThinkPad worked correctly, may be relevant when investigating interaction between Windows Search/MAPI16 and newer hardware platforms.
Hornblower409 18,510 Reputation points

2026-09-24T13:05:26.9266667+00:00
@Marek Majewski said

I have already submitted this to Microsoft Support / Feedback Hub. If anyone from Microsoft is monitoring this thread, it would be useful to have this escalated to the Windows Search / Outlook MAPI indexing engineering team

No one from Microsoft Support monitors this forum. If you want to start a Support Escalation case you have to initiate it using the standard channels.

Qualified MS 365 Subscriptions only
https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-support

Classic Outlook In App Support
Help -> Contact Support

Free Chat Support

Open a browser to https://support.microsoft.com/en-us/home/contact

Tell us your problem: {Whatever}

[Get Help] {Scroll down to the bottom of the page} [Sign in to Contact Support]

Sign in with any Microsoft account

Products and services: "Microsoft 365 and Office"

Category: "Outlook"

[Confirm]

Choose a support option -> "Chat with a support agent in your web browser"
Marek Majewski 40 Reputation points

2026-09-24T13:20:12.04+00:00

Thank you for your reply.

The issue has already been submitted to both Microsoft Support and Feedback Hub.

Based on the troubleshooting performed so far, the problem appears to be more complex than a standard Outlook search or indexing issue. The HTML message body is available through MAPI, but it is not being added to System.Search.Contents when indexed through the MAPI16 Search Protocol Handler.

I am still waiting for a response from Microsoft Support, although at this point I am not particularly optimistic that I will receive a technical answer or a concrete solution. If I do receive any useful findings, workaround, or confirmation of the issue, I will update this thread.
Bruce Hsueh 5 Reputation points

2026-09-26T03:54:48.3033333+00:00

I'm facing the same issue.

I have several PST files, each around 50 GB. They worked fine on my old Dell Inspiron 14 (11th Gen Intel CPU) with Microsoft 365. I could search the email content normally, including the message body.

However, after transferring the same PST files to a new Acer laptop with an Intel Core Ultra 7 processor and Microsoft 365, Outlook can no longer search the email body/content properly. It can find emails based on the subject and sender, but the content within the emails cannot be found.

This is really frustrating and is causing significant problems in my daily work, especially because I have a large number of historical emails that I need to search.

For now, the only workaround I have found is to use email archiving software to search the email content instead of Outlook.
Hornblower409 18,510 Reputation points

2026-09-26T04:26:40.4633333+00:00
@Bruce Hsueh said

Outlook can no longer search the email body/content properly. It can find emails based on the subject and sender, but the content within the emails cannot be found.

Does your search work correctly when running Outlook in Safe Mode, like Marek?
https://support.microsoft.com/en-us/office/open-outlook-in-safe-mode-f394c2ee-b2af-e97a-64ee-35cd24414811

Does your search work correctly if you disable the Windows Search and use the native (slow) Outlook search?

File -> Options -> Search -> [Indexing Options ...]

On the "Indexing Options" dialog: [Modify]

On the "Indexed Locations" dialog: Uncheck "Microsoft Outlook"

[OK] [Close] your way out.

Restart Outlook.

Do a Search Test

Re-enable Windows Indexed Search

If Safe Mode or using native Outlook Search works OK, please come back here and advise.

Or, if you are reasonably Windows proficient, you can try the Windows Search Troubleshooter "Virtual Agent" at https://learn.microsoft.com/en-us/troubleshoot/windows-client/shell-experience/fix-problems-in-windows-search
bernard Andri 15 Reputation points

2026-09-26T18:48:19.1+00:00

Following up on my last message from September 8, I uninstalled Office 2024 and installed Office 2019 on my new laptop, but the same problem persists: I can’t search within the body of messages if they’re in HTML format, whereas on my old laptop, the search function worked correctly.

All other settings (Windows Search, COM add-ins, etc.) are, however, exactly the same..
bernard Andri 15 Reputation points

2026-09-26T21:03:45.8933333+00:00

Following up on my last message from September 8, I uninstalled Office 2024 and installed Office 2019 on my new laptop, but the same problem persists: I can’t search within the body of messages if they’re in HTML format, whereas on my old laptop, the search function worked correctly.

All other settings (Windows Search, COM add-ins, etc.) are, however, exactly the same..
PBer 0 Reputation points

2026-09-29T18:39:00.2+00:00

I have been having the exact same issue with a 1Mb pst file. Plain text emails are searcheable, not the body of HTML emails. Safe mode works fine.

Like this for at least a week.

Office 2024 LTSC.
Bruce Hsueh 5 Reputation points

2026-10-01T09:25:59.7466667+00:00

Here are the results of the troubleshooting steps:

Here are the results of the troubleshooting steps: Safe Mode: Body search works properly, though it occasionally fails when searching across multiple PST files. Disabling Windows Search Indexing: Unchecking "Microsoft Outlook" under Indexed Locations fixed the search issue, and searching across PST files works as well. However, the search process is extremely slow. Once I re-checked "Microsoft Outlook" and let it rebuild the index, the search failed to work again. Any further suggestions on how to resolve this indexing issue?
PBer 0 Reputation points

2026-10-01T12:59:52.0233333+00:00

I did a complete uninstall of Office 2024 and reinstalled it, still HTML emails are not indexed. Slow search works. Must need a complete windows reinstall, mine is 11mo old so this is wasted time. MS has been messing with Search with Semantic AI and other stuff. I dont know why this happened.
PBer 0 Reputation points

2026-10-01T13:01:48.5466667+00:00

and they have been phasing out native apps in favor of web apps and Webview. Who knows what they did to search.
Hornblower409 18,510 Reputation points

2026-10-01T14:57:52.0333333+00:00
All,

I think we've pretty well established that:

The problem is Windows Search

Windows Search Troubleshooter doesn't fix it

Rebuilding the Windows Search Index doesn't fix it

Office Outlook Repair doesn't fix it

May be related to the PC hardware. Fails on newer models.

Only workaround is disable Windows Search and use slow Outlook native Search

Any corrections or additions?

Anyone heard back from Microsoft Support? Even if only "Yes it's a bug. We're working on it"
PBer 0 Reputation points

2026-10-02T14:40:09.9566667+00:00

Marek, If it is hardware-related, then a complete windows and office reinstall will likely not fix it. I have an old SSD i can swap with an older version of windows, im tempted to swap SSDs, if the problem persists clearly it is not a settings or a corrupted process, but rather hardware (weird that hardware controls search results) or a new bug in a new windows/office version.
bernard Andri 15 Reputation points

2026-10-03T13:48:54.3766667+00:00

I'll add one surprising detail. Even if the email is in HTML format, the search still highlights a searched-for word in yellow within the body of the email—provided that word also appears in the email's subject line or in an attachment. If the word appears only in the body of the text, the email does not appear in the search results.
bernard Andri 15 Reputation points

2026-10-03T13:53:29.78+00:00

I'll add one surprising detail. Even if the email is in HTML format, the search still highlights a searched-for word in yellow within the body of the email—provided that word also appears in the email's subject line or in an attachment. If the word appears only in the body of the text, the email does not appear in the search results.
PBer 0 Reputation points

2026-10-06T15:54:38.6233333+00:00

This is close

https://support.microsoft.com/en-us/support/known-issues/classic-outlook-issues-with-service-assisted-search-for-shared-mailboxes
Hornblower409 18,510 Reputation points

2026-10-06T20:43:06.06+00:00
@PBer said

This is close [issues with service assisted search]

Just for grins, did you try the workaround?

https://support.microsoft.com/en-us/support/known-issues/classic-outlook-issues-with-service-assisted-search-for-shared-mailboxes

Temporarily disable Server Assisted Search, which will fall back to the legacy Windows Desktop Search, with the following registry key:

HKEY_CURRENT_USER\software\policies\Microsoft\office\16.0\outlook\search

DWORD: DisableServerAssistedSearch

Value: 1
Marek Majewski 40 Reputation points

2026-10-12T09:07:15.33+00:00
Thanks Gabe.I have already tested an Office rollback on one of the affected machines.

The issue was reproduced with:

Microsoft 365 Version 2608, build 16.0.20326.20132

Microsoft 365 Version 2508, build 16.0.19127.20264 after rollback

Office 2024

The behavior was identical in all cases.

In addition, another user in this thread tested Office 2019 on his new PC and the HTML body search issue still remained, while it worked correctly on his older PC.

This seems to make a regression in a specific Outlook build less likely and points more towards the Windows Search / MAPI16 indexing path.

In my tests, the affected HTML message is present in the Windows Search index as a mapi16:// item and subject/sender are indexed correctly. PR_HTML and PR_BODY_W are both present, and PR_BODY_W contains the complete readable body text. However, a direct query against System.Search.Contents for a unique word existing only in the HTML body returns Rows.Count = 0.

The same message saved as a .msg file in a normally indexed Windows folder is indexed correctly, including its HTML body.
bernard Andri 15 Reputation points

2026-10-12T15:58:54.64+00:00

As I still hadn’t found a solution to my problem, I decided to reinstall Windows 11 from an installation USB stick, to remove all HP software from my EliteBook 8 G1i. I then reinstalled Office 2024 Home and Small Business Edition, using a licence purchased directly from the Microsoft website (I had some doubts about the origin of my old licence).

I did not copy over any old PST files. I created a new profile and a new email account with a new address. I sent myself two emails from my smartphone using my private address. I checked in ‘Indexing Options’ that the indexing was complete, and did the same via the ‘Indexing Status’ button in Outlook. The indexing was indeed complete.

Despite all this, a search for a word within the body of an HTML message yielded no results!

I switched this email to ‘plain text’ in my inbox, and then the search found the word I was looking for. I switched the email back to HTML, still in my inbox… and ran the same search again. And this time it worked, which means that Windows Search had included this search term in its index.
Gabe Bratton 95 Reputation points

2026-10-12T19:09:48.2833333+00:00

I added a Gmail POP account to my Outlook profile that already had an Outlook.com account. So far, I can search the HTML emails only looking for words that exist in the body. Maybe the issue takes some time to manifest so I will monitor.

I am using Outlook as part of Office Family subscription Version 2609 Build 20430.20146. Windows is 25H2 OS Build 26200.9457 (per running Winver command at the Windows Run prompt)

@bernard Andri there is a registry key you can set that will tell classic Outlook to use the built-in legacy search. This search works by greping the emails at search time so there is no index and it is slower, but this could workaround the issue for you. I tested to make sure it still works and it does for POP/IMAP but not for Outlook.com/M365 accounts. The registry key PreventIndexingOutlook is documented here, https://support.microsoft.com/en-us/support/known-issues/outlook-search-might-not-display-recent-emails-on-windows-11.

You will know if the legacy search is working when you see this message above the message list:

@Marek Majewski what are you using for antivirus? I have only Microsoft Defender. If you check the Event Viewer Application log for Outlook events, do you see any with search errors? In your config do you have the PST in OneDrive? I have it setup that way but the PST has not synced to OneDrive yet. If you have in OneDrive test having it outside of OneDrive if that makes any difference.
Marek Majewski 40 Reputation points

2026-10-13T07:07:10.8033333+00:00
Thanks @Gabe Bratton

The affected Outlook data file is not located in OneDrive. It is stored locally under:

C:\Users\mmajewski\AppData\Local\Microsoft\Outlook...

I also reproduced exactly the same HTML body indexing problem using a completely different email account hosted on another mail server. I tested both IMAP and POP, and the behavior was the same, so this does not appear to be specific to Gmail or to a particular mail provider.

On my main system I use ESET, but I have also reproduced the issue on a clean Windows installation without any third-party antivirus or additional software, so ESET does not appear to be the cause.

I also tested different Office versions/builds, new Outlook profiles, PST rebuilds and Windows Search index rebuilds, with no change.

There is also a very clear hardware/platform pattern in my testing.

The problem does not occur on:

Dell Latitude 7420 2-in-1

Lenovo ThinkPad X1 Carbon Gen 7

Both are running current Windows versions and the same Office versions used in my other tests.

The problem does occur on both of my newer systems:

Dell Pro 14 Premium (PA14250)

Lenovo ThinkPad X1 Carbon Gen 14 (21V70078PB)

So far, the behavior seems consistently tied to the newer hardware/platform rather than to the mail provider, Outlook profile, PST/OST file, Office version, antivirus, or Windows installation itself.

What still seems most significant is that the affected messages are present in the Windows Search index as mapi16:// items, subject/sender are indexed correctly, and PR_BODY_W contains the full readable body text, but words that exist only in the HTML body are missing from System.Search.Contents.

Also, when Windows Search indexing for Outlook is disabled, the legacy/native Outlook search finds those same HTML body terms correctly, although much more slowly.

This still seems to point specifically to the MAPI16 / Windows Search indexing path for HTML message bodies.
bernard Andri 15 Reputation points

2026-10-13T11:28:36.3733333+00:00

@Gabe Bratton I know that you can disable the Windows Search function with the index and use Outlook’s native search instead. You can also do this simply by starting Outlook in safe mode. However, in my case, this is of no use as I have 20 PST archive files, each 15GB in size. The search would be far too slow. In the meantime, I’m using Filelocator.
Turgay Oğuş 0 Reputation points

2026-10-13T16:43:53.3766667+00:00

I tried all possible solutions from AI. Nothing helped. Still no solution on body search. Just occcured on may new laptop. It is possibly related with new Copilot PCs.

Turgay
Turgay Oğuş 0 Reputation points

2026-10-13T17:39:10.2566667+00:00
On a Dell XPS DA14260 running Windows 11 25H2 and Microsoft Office LTSC Professional Plus 2024 (Outlook version 2408, build 16.0.17932.20884, 64-bit), Windows Search does not find words that appear only in HTML-formatted email bodies. Subject and sender searches work.

The issue persists across multiple clean Windows installations, Outlook profile/OST recreation, Office repair, and Windows Search index rebuilds. Disabling all COM add-ins does not resolve it.

Key diagnostic results:

Outlook Safe Mode finds HTML body text.

Saving the affected email as an MSG file allows Windows Search to find the same body text.

Excluding Microsoft Outlook from Windows Search indexing restores body searches in normal Outlook, but searches become slower.

Re-enabling Outlook indexing causes the issue to return.
Marek Majewski 40 Reputation points

2026-10-30T07:57:00.9933333+00:00

@Hornblower409

Dell Latitude 7420 (11th Gen Intel Core i7-1185G7):

9.60502.60502.{0000001D-57EE-1E5C-00B4-D0000BB1E11E} - OK.

Lenovo ThinkPad X1 Carbon Gen 14 (Intel Core Ultra 7 355, Copilot+ PC):

10.60502.60502.{0000001D-57EE-1E5C-00B4-D0000BB1E11E} – HTML body search does not work
Markus Schlegel 0 Reputation points

2026-11-01T09:38:54.69+00:00

I have exactly the same issues like Marek Majewski already perfectly has described and analyzed!
I am spending already many days on this Outlook 2024 classis HTML-Email search issue and AI is not able to help me further. At least I now know that the search only fails with HTML - emails. Search in plain-text emails works like expected. Also the Windows file explorer search with an exported HTML email to a MSG file works like expected.

Most important, I am also using a new Lenovo ThinkPad X1 Carbon Gen 14!

Deactivating indexed search via registry entry "Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search", then DWord "PreventIndexingOutlooks" set to 1 works but is incredibly slow and not usable for me (can take up to 30minutes for one search and completely kills productivity).

It is a shame that Microsoft does not react better and faster on this issue - this completely kills any productivity in daily business"

Currently I am doing email search on my old computer which is very, very time consuming.

I also tried third party software like Kernel Outlook PST Viewer, but they also don´t search in HTML - email bodies.

I hope that there will be a fix / solution soon.
Thanks for your hard work in here - at least I now know that I am not the only person with such an unbelievable issue.

Please keep posting as soon as there are any news on this issue. Thanks a lot.
Hornblower409 18,510 Reputation points

2026-11-01T12:03:25.8266667+00:00
@Markus Schlegel said

I have exactly the same issues

If you would please:

Run this PowerShell query on your PC.

Reply with the IndeexrCatalogVersion value

(Leave a comment here is you are not sure how to run a PowerShell query)

Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows Search" | Select-Object IndexerCatalogVersion
Markus Schlegel 0 Reputation points

2026-11-01T12:27:33.0366667+00:00

Thanks for your speedy reply, @Hornblower409 - much appreciated :-)
Attached you will find the information requested:

Hope this will help to identify this massive issue... Currently I am indexing my Outlook system again - strangely this took about 5 hours yesterday, but today the complete new indexing already took more than 15 hours and there are still many items left for indexing, most probably it will take some more 5 hours...
Hornblower409 18,510 Reputation points

2026-11-01T13:17:09.8666667+00:00

@Markus Schlegel said

IndexerCatalogVersion = 10.60502.60502

Thank you. That adds another affected PC reporting IndexerCatalogVersion = 10.x. This does not prove causation, but it is currently the strongest measurable correlation reported in this thread.

I am indexing my Outlook system again

I can't speak to why you are seeing such a wide variation in index rebuild times. Another mystery on top of all the others surrounding this issue?

6 answers

Your answer

Hornblower409 18,510 Reputation points

2026-09-08T00:09:01.6466667+00:00

@bernard Andri said

Search works as expected when running Outlook in Safe Mode

Since Safe Mode's primary impact is to disable all Add-ins, it might be work trying another test:

Start Outlook normally.

File → Options → Add-ins.

Manage COM Add-ins → Go.

Take a screen shot of the dialog, or make notes, so you know which Add-Ins are normally enabled.

Disable everything by unchecking it.

Restart Outlook normally.

Do your search test.
Zahid Barrera Ramirez 465 Reputation points

2026-09-08T01:05:11.89+00:00

@Hornblower409 Good point — I agree this is an important test before going deeper into the Windows Search/IFilter path.

Safe Mode disables COM add-ins and other Outlook extensions, so the fact that search works there does not by itself prove that Outlook is bypassing Windows Search.

I would disable all COM add-ins as you suggested, restart Outlook normally, and repeat the HTML-body search test.

If the issue disappears, I would then re-enable the add-ins one at a time to identify the component interfering with search.

If the issue remains with all COM add-ins disabled, that would make the Windows Search/indexing path more interesting again, especially given that:

the issue reproduces with a new profile and clean PST,

indexing reports 0 items remaining,

Plain Text messages are searchable by body,

HTML message bodies are not,

and Microsoft expects the Outlook MSG IFilter to be correctly registered for Outlook content indexing.

At that point I would compare the filter/protocol-handler activity between normal and Safe Mode, potentially using ProcMon against SearchFilterHost.exe and SearchProtocolHost.exe.

Thanks for pointing this out — disabling the add-ins separately is definitely a cleaner isolation step before assuming an IFilter problem.
bernard Andri 15 Reputation points

2026-09-08T18:15:06.0166667+00:00

I’d already tried disabling all COM add-ins, but the problem persists
bernard Andri 15 Reputation points

2026-09-08T18:19:58.3566667+00:00

I should point out that I’ve just changed my computer. On the old one, which ran Windows 11 but had Office 2019, the search function worked. On the new computer (still an HP EliteBook), I’ve installed Office 2024. Do you think it would be worth trying to install Office 2019 instead of Office 2024 on my new laptop?
Zahid Barrera Ramirez 465 Reputation points

2026-09-08T18:24:53.6933333+00:00

@bernard Andri Yes, that comparison is very useful, but I would not replace Office 2024 with Office 2019 just yet.

The fact that the same type of POP/PST configuration worked correctly on Windows 11 with Outlook 2019, while the new Windows 11 + Outlook 2024 installation does not index HTML message bodies, makes the Outlook/Office version or its Windows Search integration a much stronger suspect.

Before downgrading, I would complete the COM Add-ins test Bernard suggested earlier:

Start Outlook 2024 normally.

Disable all COM Add-ins.

Restart Outlook normally.

Test a search for a word that exists only inside the HTML body of a message.

If the problem remains, I would then consider Office 2019 a very useful diagnostic test — not necessarily the permanent solution.

If you still have access to the old computer, an even better comparison would be to check the Windows Search/File Types configuration on both machines, particularly the Outlook-related filter registrations. That could show us whether Office 2019 and Office 2024 registered different search components.

If Office 2019 indexes the same test PST correctly on the new computer while Office 2024 does not, that would be very strong evidence that we are dealing with an Office 2024/Windows Search integration issue rather than corrupted PST data, the Outlook profile, or Windows itself.

So yes, testing Office 2019 could be worthwhile — but I would use it as a controlled troubleshooting step after testing Outlook 2024 with all COM Add-ins disabled.

Also, before changing Office versions, I would make sure you have a backup of the PST files and your Office 2019 installation/license available.

If this answer helped, please consider marking it as helpful. It helps other users experiencing the same issue find the troubleshooting path more easily.
Hornblower409 18,510 Reputation points

2026-09-08T18:57:56.48+00:00

@bernard Andri said

Do you think it would be worth trying to install Office 2019 instead of Office 2024 on my new laptop?

Before you go down that path, I would suggest that you bring in Microsoft Support. They can examine your setup and pull diagnostic logs from Outlook and Windows Indexer.

For Classic Outlook In-App Chat Support, do Help -> Contact Support
Hornblower409 18,510 Reputation points

2026-09-24T13:05:26.9266667+00:00

@Marek Majewski said

I have already submitted this to Microsoft Support / Feedback Hub. If anyone from Microsoft is monitoring this thread, it would be useful to have this escalated to the Windows Search / Outlook MAPI indexing engineering team

No one from Microsoft Support monitors this forum. If you want to start a Support Escalation case you have to initiate it using the standard channels.

Qualified MS 365 Subscriptions only
https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-support

Classic Outlook In App Support
Help -> Contact Support

Free Chat Support

Open a browser to https://support.microsoft.com/en-us/home/contact

Tell us your problem: {Whatever}

[Get Help] {Scroll down to the bottom of the page} [Sign in to Contact Support]

Sign in with any Microsoft account

Products and services: "Microsoft 365 and Office"

Category: "Outlook"

[Confirm]

Choose a support option -> "Chat with a support agent in your web browser"
Marek Majewski 40 Reputation points

2026-09-24T13:20:12.04+00:00

Thank you for your reply.

The issue has already been submitted to both Microsoft Support and Feedback Hub.

Based on the troubleshooting performed so far, the problem appears to be more complex than a standard Outlook search or indexing issue. The HTML message body is available through MAPI, but it is not being added to System.Search.Contents when indexed through the MAPI16 Search Protocol Handler.

I am still waiting for a response from Microsoft Support, although at this point I am not particularly optimistic that I will receive a technical answer or a concrete solution. If I do receive any useful findings, workaround, or confirmation of the issue, I will update this thread.
Bruce Hsueh 5 Reputation points

2026-09-26T03:54:48.3033333+00:00

I'm facing the same issue.

I have several PST files, each around 50 GB. They worked fine on my old Dell Inspiron 14 (11th Gen Intel CPU) with Microsoft 365. I could search the email content normally, including the message body.

However, after transferring the same PST files to a new Acer laptop with an Intel Core Ultra 7 processor and Microsoft 365, Outlook can no longer search the email body/content properly. It can find emails based on the subject and sender, but the content within the emails cannot be found.

This is really frustrating and is causing significant problems in my daily work, especially because I have a large number of historical emails that I need to search.

For now, the only workaround I have found is to use email archiving software to search the email content instead of Outlook.
Hornblower409 18,510 Reputation points

2026-09-26T04:26:40.4633333+00:00

@Bruce Hsueh said

Outlook can no longer search the email body/content properly. It can find emails based on the subject and sender, but the content within the emails cannot be found.

Does your search work correctly when running Outlook in Safe Mode, like Marek?
https://support.microsoft.com/en-us/office/open-outlook-in-safe-mode-f394c2ee-b2af-e97a-64ee-35cd24414811

Does your search work correctly if you disable the Windows Search and use the native (slow) Outlook search?

File -> Options -> Search -> [Indexing Options ...]

On the "Indexing Options" dialog: [Modify]

On the "Indexed Locations" dialog: Uncheck "Microsoft Outlook"

[OK] [Close] your way out.

Restart Outlook.

Do a Search Test

Re-enable Windows Indexed Search

If Safe Mode or using native Outlook Search works OK, please come back here and advise.

Or, if you are reasonably Windows proficient, you can try the Windows Search Troubleshooter "Virtual Agent" at https://learn.microsoft.com/en-us/troubleshoot/windows-client/shell-experience/fix-problems-in-windows-search
bernard Andri 15 Reputation points

2026-09-26T18:48:19.1+00:00

Following up on my last message from September 8, I uninstalled Office 2024 and installed Office 2019 on my new laptop, but the same problem persists: I can’t search within the body of messages if they’re in HTML format, whereas on my old laptop, the search function worked correctly.

All other settings (Windows Search, COM add-ins, etc.) are, however, exactly the same..
bernard Andri 15 Reputation points

2026-09-26T21:03:45.8933333+00:00

Following up on my last message from September 8, I uninstalled Office 2024 and installed Office 2019 on my new laptop, but the same problem persists: I can’t search within the body of messages if they’re in HTML format, whereas on my old laptop, the search function worked correctly.

All other settings (Windows Search, COM add-ins, etc.) are, however, exactly the same..
PBer 0 Reputation points

2026-09-29T18:39:00.2+00:00

I have been having the exact same issue with a 1Mb pst file. Plain text emails are searcheable, not the body of HTML emails. Safe mode works fine.

Like this for at least a week.

Office 2024 LTSC.
Bruce Hsueh 5 Reputation points

2026-10-01T09:25:59.7466667+00:00

Here are the results of the troubleshooting steps:

Here are the results of the troubleshooting steps: Safe Mode: Body search works properly, though it occasionally fails when searching across multiple PST files. Disabling Windows Search Indexing: Unchecking "Microsoft Outlook" under Indexed Locations fixed the search issue, and searching across PST files works as well. However, the search process is extremely slow. Once I re-checked "Microsoft Outlook" and let it rebuild the index, the search failed to work again. Any further suggestions on how to resolve this indexing issue?
PBer 0 Reputation points

2026-10-01T12:59:52.0233333+00:00

I did a complete uninstall of Office 2024 and reinstalled it, still HTML emails are not indexed. Slow search works. Must need a complete windows reinstall, mine is 11mo old so this is wasted time. MS has been messing with Search with Semantic AI and other stuff. I dont know why this happened.
PBer 0 Reputation points

2026-10-01T13:01:48.5466667+00:00

and they have been phasing out native apps in favor of web apps and Webview. Who knows what they did to search.
Hornblower409 18,510 Reputation points

2026-10-01T14:57:52.0333333+00:00

All,

I think we've pretty well established that:

The problem is Windows Search

Windows Search Troubleshooter doesn't fix it

Rebuilding the Windows Search Index doesn't fix it

Office Outlook Repair doesn't fix it

May be related to the PC hardware. Fails on newer models.

Only workaround is disable Windows Search and use slow Outlook native Search

Any corrections or additions?

Anyone heard back from Microsoft Support? Even if only "Yes it's a bug. We're working on it"
PBer 0 Reputation points

2026-10-02T14:40:09.9566667+00:00

Marek, If it is hardware-related, then a complete windows and office reinstall will likely not fix it. I have an old SSD i can swap with an older version of windows, im tempted to swap SSDs, if the problem persists clearly it is not a settings or a corrupted process, but rather hardware (weird that hardware controls search results) or a new bug in a new windows/office version.
bernard Andri 15 Reputation points

2026-10-03T13:48:54.3766667+00:00

I'll add one surprising detail. Even if the email is in HTML format, the search still highlights a searched-for word in yellow within the body of the email—provided that word also appears in the email's subject line or in an attachment. If the word appears only in the body of the text, the email does not appear in the search results.
bernard Andri 15 Reputation points

2026-10-03T13:53:29.78+00:00

I'll add one surprising detail. Even if the email is in HTML format, the search still highlights a searched-for word in yellow within the body of the email—provided that word also appears in the email's subject line or in an attachment. If the word appears only in the body of the text, the email does not appear in the search results.
PBer 0 Reputation points

2026-10-06T15:54:38.6233333+00:00

This is close

https://support.microsoft.com/en-us/support/known-issues/classic-outlook-issues-with-service-assisted-search-for-shared-mailboxes
Hornblower409 18,510 Reputation points

2026-10-06T20:43:06.06+00:00

@PBer said

This is close [issues with service assisted search]

Just for grins, did you try the workaround?

https://support.microsoft.com/en-us/support/known-issues/classic-outlook-issues-with-service-assisted-search-for-shared-mailboxes

Temporarily disable Server Assisted Search, which will fall back to the legacy Windows Desktop Search, with the following registry key:

HKEY_CURRENT_USER\software\policies\Microsoft\office\16.0\outlook\search

DWORD: DisableServerAssistedSearch

Value: 1
Marek Majewski 40 Reputation points

2026-10-12T09:07:15.33+00:00

Thanks Gabe.I have already tested an Office rollback on one of the affected machines.

The issue was reproduced with:

Microsoft 365 Version 2608, build 16.0.20326.20132

Microsoft 365 Version 2508, build 16.0.19127.20264 after rollback

Office 2024

The behavior was identical in all cases.

In addition, another user in this thread tested Office 2019 on his new PC and the HTML body search issue still remained, while it worked correctly on his older PC.

This seems to make a regression in a specific Outlook build less likely and points more towards the Windows Search / MAPI16 indexing path.

In my tests, the affected HTML message is present in the Windows Search index as a mapi16:// item and subject/sender are indexed correctly. PR_HTML and PR_BODY_W are both present, and PR_BODY_W contains the complete readable body text. However, a direct query against System.Search.Contents for a unique word existing only in the HTML body returns Rows.Count = 0.

The same message saved as a .msg file in a normally indexed Windows folder is indexed correctly, including its HTML body.
bernard Andri 15 Reputation points

2026-10-12T15:58:54.64+00:00

As I still hadn’t found a solution to my problem, I decided to reinstall Windows 11 from an installation USB stick, to remove all HP software from my EliteBook 8 G1i. I then reinstalled Office 2024 Home and Small Business Edition, using a licence purchased directly from the Microsoft website (I had some doubts about the origin of my old licence).

I did not copy over any old PST files. I created a new profile and a new email account with a new address. I sent myself two emails from my smartphone using my private address. I checked in ‘Indexing Options’ that the indexing was complete, and did the same via the ‘Indexing Status’ button in Outlook. The indexing was indeed complete.

Despite all this, a search for a word within the body of an HTML message yielded no results!

I switched this email to ‘plain text’ in my inbox, and then the search found the word I was looking for. I switched the email back to HTML, still in my inbox… and ran the same search again. And this time it worked, which means that Windows Search had included this search term in its index.
Gabe Bratton 95 Reputation points

2026-10-12T19:09:48.2833333+00:00

I added a Gmail POP account to my Outlook profile that already had an Outlook.com account. So far, I can search the HTML emails only looking for words that exist in the body. Maybe the issue takes some time to manifest so I will monitor.

I am using Outlook as part of Office Family subscription Version 2609 Build 20430.20146. Windows is 25H2 OS Build 26200.9457 (per running Winver command at the Windows Run prompt)

@bernard Andri there is a registry key you can set that will tell classic Outlook to use the built-in legacy search. This search works by greping the emails at search time so there is no index and it is slower, but this could workaround the issue for you. I tested to make sure it still works and it does for POP/IMAP but not for Outlook.com/M365 accounts. The registry key PreventIndexingOutlook is documented here, https://support.microsoft.com/en-us/support/known-issues/outlook-search-might-not-display-recent-emails-on-windows-11.

You will know if the legacy search is working when you see this message above the message list:

@Marek Majewski what are you using for antivirus? I have only Microsoft Defender. If you check the Event Viewer Application log for Outlook events, do you see any with search errors? In your config do you have the PST in OneDrive? I have it setup that way but the PST has not synced to OneDrive yet. If you have in OneDrive test having it outside of OneDrive if that makes any difference.
bernard Andri 15 Reputation points

2026-10-13T11:28:36.3733333+00:00

@Gabe Bratton I know that you can disable the Windows Search function with the index and use Outlook’s native search instead. You can also do this simply by starting Outlook in safe mode. However, in my case, this is of no use as I have 20 PST archive files, each 15GB in size. The search would be far too slow. In the meantime, I’m using Filelocator.
Turgay Oğuş 0 Reputation points

2026-10-13T16:43:53.3766667+00:00

I tried all possible solutions from AI. Nothing helped. Still no solution on body search. Just occcured on may new laptop. It is possibly related with new Copilot PCs.

Turgay
Turgay Oğuş 0 Reputation points

2026-10-13T17:39:10.2566667+00:00

On a Dell XPS DA14260 running Windows 11 25H2 and Microsoft Office LTSC Professional Plus 2024 (Outlook version 2408, build 16.0.17932.20884, 64-bit), Windows Search does not find words that appear only in HTML-formatted email bodies. Subject and sender searches work.

The issue persists across multiple clean Windows installations, Outlook profile/OST recreation, Office repair, and Windows Search index rebuilds. Disabling all COM add-ins does not resolve it.

Key diagnostic results:

Outlook Safe Mode finds HTML body text.

Saving the affected email as an MSG file allows Windows Search to find the same body text.

Excluding Microsoft Outlook from Windows Search indexing restores body searches in normal Outlook, but searches become slower.

Re-enabling Outlook indexing causes the issue to return.
Marek Majewski 40 Reputation points

2026-10-30T07:57:00.9933333+00:00

@Hornblower409

Dell Latitude 7420 (11th Gen Intel Core i7-1185G7):

9.60502.60502.{0000001D-57EE-1E5C-00B4-D0000BB1E11E} - OK.

Lenovo ThinkPad X1 Carbon Gen 14 (Intel Core Ultra 7 355, Copilot+ PC):

10.60502.60502.{0000001D-57EE-1E5C-00B4-D0000BB1E11E} – HTML body search does not work
Markus Schlegel 0 Reputation points

2026-11-01T09:38:54.69+00:00

I have exactly the same issues like Marek Majewski already perfectly has described and analyzed!
I am spending already many days on this Outlook 2024 classis HTML-Email search issue and AI is not able to help me further. At least I now know that the search only fails with HTML - emails. Search in plain-text emails works like expected. Also the Windows file explorer search with an exported HTML email to a MSG file works like expected.

Most important, I am also using a new Lenovo ThinkPad X1 Carbon Gen 14!

Deactivating indexed search via registry entry "Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search", then DWord "PreventIndexingOutlooks" set to 1 works but is incredibly slow and not usable for me (can take up to 30minutes for one search and completely kills productivity).

It is a shame that Microsoft does not react better and faster on this issue - this completely kills any productivity in daily business"

Currently I am doing email search on my old computer which is very, very time consuming.

I also tried third party software like Kernel Outlook PST Viewer, but they also don´t search in HTML - email bodies.

I hope that there will be a fix / solution soon.
Thanks for your hard work in here - at least I now know that I am not the only person with such an unbelievable issue.

Please keep posting as soon as there are any news on this issue. Thanks a lot.
Hornblower409 18,510 Reputation points

2026-11-01T12:03:25.8266667+00:00

@Markus Schlegel said

I have exactly the same issues

If you would please:

Run this PowerShell query on your PC.

Reply with the IndeexrCatalogVersion value

(Leave a comment here is you are not sure how to run a PowerShell query)

Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows Search" | Select-Object IndexerCatalogVersion
Markus Schlegel 0 Reputation points

2026-11-01T12:27:33.0366667+00:00

Thanks for your speedy reply, @Hornblower409 - much appreciated :-)
Attached you will find the information requested:

Hope this will help to identify this massive issue... Currently I am indexing my Outlook system again - strangely this took about 5 hours yesterday, but today the complete new indexing already took more than 15 hours and there are still many items left for indexing, most probably it will take some more 5 hours...
Hornblower409 18,510 Reputation points

2026-11-01T13:17:09.8666667+00:00

@Markus Schlegel said

IndexerCatalogVersion = 10.60502.60502

Thank you. That adds another affected PC reporting IndexerCatalogVersion = 10.x. This does not prove causation, but it is currently the strongest measurable correlation reported in this thread.

I am indexing my Outlook system again

I can't speak to why you are seeing such a wide variation in index rebuild times. Another mystery on top of all the others surrounding this issue?

Answer 1

Felipe Ferreira 5

Same issue here, confirmed with the same diagnostics.

Environment: Classic Outlook (Microsoft 365, 16.0.20527.20088, 64-bit), Windows 11 build 26100/26300, Lenovo Yoga Slim 7i, Intel Core Ultra 7 258V (Copilot+ PC). IMAP accounts (custom domain and Gmail).

Subject, sender and recipients are indexed; words that appear only in the body of HTML emails are never found.
A test email sent as plain text IS found; the same test as HTML is NOT.
SystemIndex query CONTAINS(System.Search.Contents, 'term') returns 0 for HTML items (mapi16://).
The gather log (SystemIndex.gthr) shows thousands of 0x80041206 (PRTH_E_SERVER_ERROR) entries on mapi16 items.
On an older laptop (Intel i5-10210U) with the same Windows build, same Office build and the same accounts, body search works. The only relevant difference I found: IndexerCatalogVersion = 10 on the affected machine vs 9 on the working one.

Tried without success: multiple index rebuilds, recreating the account, a brand-new Outlook profile, Office Online Repair, fixing the default data file, DisableServerAssistedSearch = 1. Only PreventIndexingOutlook = 1 works (slow legacy search).

Reported via Help > Feedback > Report a problem as well.

Hornblower409 18,510 Reputation points

2026-10-28T23:47:00.32+00:00
@Felipe Ferreira said

On an older laptop (Intel i5-10210U) with the same Windows build, same Office build and the same accounts, body search works. The only relevant difference I found: IndexerCatalogVersion = 10 on the affected machine vs 9 on the working one.

Thank you very much for the report. That's one of the few testable conditions anyone has reported.

1 -- Please confirm what you used to obtain IndexerCatalogVersion. Was it:

PS> Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows Search" | Select-Object IndexerCatalogVersion IndexerCatalogVersion --------------------- 9.60502.60502.{00000001-57EE-1E5C-00B4-D0000BB1E11E}

2 -- Could you please post the full output for both PCs.

Once confirmed, I'll go back to some of the other affected users and ask for the same info.
Deleted

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Felipe Ferreira 5 Reputation points

2026-10-29T02:27:17.4633333+00:00
@Hornblower409 Thanks. Yes, I used:

Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows Search"

Both PCs return the same values and subkeys (including SemanticIndexer). The only difference is IndexerCatalogVersion:

Affected (Lenovo Yoga Slim 7i, Core Ultra 7 258V): 10.60502.60502.{00000001-57EE-1E5C-00B4-D0000BB1E11E}

Working (Dell Inspiron 5490, i5-10210U): 9.60502.60502.{00000001-57EE-1E5C-00B4-D0000BB1E11E}

CurrentVersion is 10.0.26100.9711 on both. The affected PC still reports 10 after three index rebuilds.
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Answer 2

Submit a Problem Report

Even if you don't want to try Microsoft Support, or you did and they weren't any help, I would still suggest that you submit a Problem Report. Every Report moves this problem a tiny bit higher up on the Microsoft Fixit List. (gotta be one long list).

From the Classic Outlook main menu do: Help -> Feedback -> Report a problem.

For the problem description field ("What did you dislike?"), Copilot suggest this as a concise description of the issue you can copy/paste. (Feel free to improvise).

Windows Search indexing in Classic Outlook does not index HTML email body content stored in PST files. Subject, sender, attachment names, and plain-text message bodies are searchable, but words appearing only in HTML message bodies are not found. Rebuilding the index, Office Repair, and disabling add-ins do not resolve the issue. Disabling Windows indexing and using native Outlook search restores correct results. See also: Q&A thread at https://learn.microsoft.com/en-us/answers/questions/5995996/

"May we contact you about your feedback?" - I'd suggest "Yes", but your call.

[Submit]

Answer 3

Hornblower409 18,510

@bernard Andri @Bruce Hsueh @Gabe Bratton @Marek Majewski @PBer @Turgay Oğuş

We have a possible indicator from the testing done by @Felipe Ferreira

He reports that a PC with broken Search is showing IndexerCatalogVersion 10.x and a working one reports 9.x. This may be unrelated, but it is one of the few testable differences identified so far.

If you would please:

Run this PowerShell query on any PCs you have been testing.
Reply with the IndeexrCatalogVersion value and if Search on that PC is working OK or not.

Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows Search" | Select-Object IndexerCatalogVersion

e.g. For my Win11 PC where Search is OK: 9.60502.60502 OK

Deleted

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Marek Majewski 40 Reputation points

2026-10-30T11:11:22.0166667+00:00

@Hornblower409, below are my results:

Dell Latitude 7420 (11th Gen Intel Core i7-1185G7):

9.60502.60502.{0000001D-57EE-1E5C-00B4-D0000BB1E11E} – OK.

Lenovo ThinkPad X1 Carbon Gen 14 (Intel Core Ultra 7 355, Copilot+ PC):

10.60502.60502.{0000001D-57EE-1E5C-00B4-D0000BB1E11E} – HTML body search does not work.
Hornblower409 18,510 Reputation points

2026-10-30T16:06:18.3866667+00:00

@Marek Majewski

Thank you for the report. This is the second report showing IndexerCatalogVersion 9.x -> OK, 10.x -> Broken. This is the first measurable correlation reported.
bernard Andri 15 Reputation points

2026-10-30T20:27:25.71+00:00

@Hornblower409, below are my results :

HP EliteBook 8 G1i 16 inc Notebook Next GEn AI PC
Intel(R) Core(TM) Ultra 7 258V (2.20 GHz)

10.60502.60502.{00000003-57EE-1E5C-00B4-D0000BB1E11E}

HTML body search does not work.

Tomorrow i will do the same test with my previous EliteBook (same Windows but with Office 2019)
PBer 0 Reputation points

2026-11-01T17:28:56.04+00:00

Bad search is on a relatively new Lunar lake Surface pro.

Indexer 10.60502.60502
bernard Andri 15 Reputation points

2026-11-01T19:39:33.0133333+00:00

@Hornblower409, below are my results with my old HP Elite 850 ( search works) wtith same windows 11 but office 2019:

9.60502.60502.{00000003-57EE-1E5C-00B4-D0000BB1E11E}
Markus Schlegel 0 Reputation points

2026-11-01T19:55:49.24+00:00

@Hornblower409, below are my results with my brand new Lenovo ThinkPad X1 Carbon Gen 14 with Windows 11 Pro and Outlook 2024 Classic (search does NOT work for HTML based Emails -> works for email - subject, but not for email - content, exactly as e.g. Marek Majewski has reported):
Hornblower409 18,510 Reputation points

2026-11-01T22:03:25.6533333+00:00
To: All

Thank you for your reports. We now have:

Working = 4 systems, all reporting IndexerCatalogVersion 9.x

Failing = 5 systems, all reporting IndexerCatalogVersion 10.x

Contradictory samples = 0

With millions of people running the same IndexerCatalogVersion 10.x setup with no problems, there is obviously another factor involved. But I will pass this information to a senior volunteer moderator and see what our next steps might be.

And, if you haven't already, please submit a Problem Report.
See https://learn.microsoft.com/en-us/answers/a/12985026
Markus Schlegel 0 Reputation points

2026-11-02T07:31:28.7866667+00:00

@Hornblower409 : Thanks for your reply, information and effort. Is there any (easy) way to just replace the IndexerCatalogVersion 10.x to the older IndexerCatalogVersion 9.x?
Hornblower409 18,510 Reputation points

2026-11-03T01:00:44.37+00:00

@Markus Schlegel said

Is there any (easy) way to just replace the IndexerCatalogVersion 10.x to the older IndexerCatalogVersion 9.x?

Fix?

From my research, there is just not enough information about IndexerCatalogVersion to even speculate about a possible rollback.

At this time my guess is that it is only a marker for the problem, not a cause. Have to assume that there are thousands of PC that are running IndexerCatalogVersion 10.x + Outlook 2024 + PST with no problems? There is some other factor, unique to the PCs that have the issue?

Escalation Path?

I have not been able to find an escalation path for this problem. All we can do is to continue to submit Problem Reports (see https://learn.microsoft.com/en-us/answers/a/12985026) or Contact Support (has not been any help so far).

AI Help?

I feed this whole thread to my MS 365 Copilot and it failed to produce anything useful. If someone has access to a higher tier AI could also give it a try?
Turgay Oğuş 0 Reputation points

2026-11-03T07:35:28.8666667+00:00

Additional Test Results – Dell XPS DA14260 / Intel Core Ultra / Windows 11 25H2

I am experiencing exactly the same HTML email body search issue on a new Dell XPS DA14260 Copilot+ PC.

System configuration:

Device: Dell XPS DA14260

Processor platform: Intel Core Ultra

Operating System: Windows 11 25H2

Office Edition: Microsoft Office LTSC Professional Plus 2024

Outlook Version: Microsoft Outlook LTSC MSO, Version 2408, Build 16.0.17932.21056 (64-bit)

Windows Search IndexerCatalogVersion:

10.60502.60502.{00000022-57EE-1E5C-00B4-D0000BB1E11E}

Problem description:

Outlook cannot find words contained in HTML-formatted email bodies. Searches for sender names and email subjects work, but searching for text that exists only in the message body returns no results.

The issue has existed since I purchased this laptop. It is not related to a recent driver or Office update.

Troubleshooting already performed:

Multiple clean Windows installations (3–4 times).

Rebuilt the Windows Search index several times.

Recreated the Outlook profile and OST file.

Tested both OST and PST data files.

Repaired Office installation.

Disabled all COM add-ins.

Updated Office LTSC 2024 to Build 17932.21056.

Updated Dell and Intel drivers, including Intel NPU, Intel Software Integrated Package, Intel Management Engine and graphics drivers.

None of these steps resolved the issue.

Important test results:

Outlook Safe Mode successfully finds text in HTML email bodies.

Saving the affected email as an .msg file allows Windows Search to find the same body text.

Disabling all COM add-ins does not resolve the issue in normal Outlook.

Excluding Microsoft Outlook from Windows Search indexing restores body-text searches in normal Outlook. Results appear after a few seconds, suggesting Outlook is using its own non-indexed search mechanism.

Re-enabling Outlook indexing causes the problem to return.

Windows Search version comparison:

My system reports:

IndexerCatalogVersion = 10.60502.60502.{00000022-57EE-1E5C-00B4-D0000BB1E11E}

This appears to match the 10.60502 version family reported by other users experiencing the same issue on newer Intel platforms.

Could this be a regression or compatibility issue in the Windows Search 10.x indexing engine, particularly its interaction with Outlook's MAPI Search Protocol Handler and HTML message body indexing?

Older Intel-based systems reportedly using Windows Search 9.60502 do not exhibit the same problem.

I would appreciate further investigation by the Windows Search and Outlook engineering teams.

The key question is whether Windows Search 10.60502 has a regression affecting HTML email body indexing through Outlook's MAPI integration.
Hornblower409 18,510 Reputation points

2026-11-03T08:01:52.8966667+00:00

@Turgay Oğuş said

Tested both OST and PST data files.

That's a new one. Had not seen any test results for an OST.

Additional Test Results – Dell XPS DA14260

You duplicated your comment when you pasted it into Q&A.

All the details are good for a Problem Report, but this isn't Microsoft Support. All I need at this point is something simple. If you want to submit a Problem Report, or engage Microsoft Support, please use your full write-up.

But to keep the clutter down on this thread, could you use the "stacked dots" menu under your comment and shorten it up a bit? Maybe to just your CPU Type, Outlook Version, IndexerCatalogVersion and (very important) "Tested both OST and PST data files".
Turgay Oğuş 0 Reputation points

2026-11-03T10:05:10.2666667+00:00

Edited and reported to MS.

Answer 4

Something to try is to revert the Office build before the issue started. If reverting helps, then it's likely an Outlook bug. If reverting does not help, then it's possibly a Windows Search issue or third-party integration.

To revert do the steps below:

Find a build from August 2026 of your respective version of Office, https://learn.microsoft.com/en-us/officeupdates/update-history-office-2024. In Step 3 below replace the example build with the build you got in the Update History page. I put the Office 2024 Retail build from August 24th in the step below already.
Open a Command Prompt in Administrator context.
Type or paste the two commands into the Command Prompt window and press Enter after each:

cd %programfiles%\Common Files\Microsoft Shared\ClickToRun

officec2rclient.exe /update user updatetoversion=16.0.20228.20158

Answer 5

Hornblower409 18,510

@PBer said

Plain text emails are searcheable, not the body of HTML emails. Safe mode works fine.

Does your search also work correctly if you disable Windows Search and use the native (slow) Outlook search?

File -> Options -> Search -> Indexing Options ...
On the "Indexing Options" dialog: [Modify]
On the "Indexed Locations" dialog: Uncheck "Microsoft Outlook"
[OK], [Close] your way out.
Restart Outlook.
Do a Search Test
Re-enable Windows Search

If using native Outlook Search works OK, you can try the Windows Search Troubleshooter "Virtual Agent" at
https://learn.microsoft.com/en-us/troubleshoot/windows-client/shell-experience/fix-problems-in-windows-search

If that doesn't help, you will need to bring in Microsoft Support:

Qualified MS 365 Subscriptions only
https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-support

Classic Outlook In-App Support
Help -> Contact Support

PBer 0 Reputation points

2026-09-29T21:20:53.36+00:00

That troubleshooter did not help, did the 6 steps.
Hornblower409 18,510 Reputation points

2026-09-29T23:58:41.1666667+00:00

@PBer said

That troubleshooter did not help, did the 6 steps.

The only other suggestion I can offer is to bring in Microsoft Support as mentioned in my previous comment.
Hornblower409 18,510 Reputation points

2026-09-30T02:23:15.0433333+00:00

@PBer said

That troubleshooter did not help, did the 6 steps.

Probably not going to fix it, but it's easy to do.
Office Outlook Repair
https://support.microsoft.com/en-us/office/lifecycle/repair-an-office-application

Outlook 2024 (POP/PST): Search does not index HTML email bodies (IFilter issue)

6 answers

Submit a Problem Report

Additional Test Results – Dell XPS DA14260 / Intel Core Ultra / Windows 11 25H2

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