Microsoft Exchange 2019: Search Results are Incomplete on Server

With Exchange 2019, Microsoft has introduced a new search engine: BigFunnel. This is the same engine that is used in Bing and in Exchange Online.

Unfortunately, sometimes, the search results are incomplete. While this might have different reasons, I am just looking at one prticular case here:

  • Incomplete search results are happening on OWA, i.e. this is an issue on the server, not on Outlook (the client)
  • The number of missing emails from the search results is visible in "BigFunnelNotIndexedCount"
  • If the a property of a not-indexed email is changed (e.g. flag the email), it will be indexed and appear in the search results from now on
  • Moving the mailbox from one Exchange database to another fixes the problem and resets the "BigFunnelNotIndexedCount" to 0

Many people have reported this behaviour, so I am surely not the only one. Even with the latest CU (CU11 as of this writing) the problem is still there, as you can see here:


To find out if a particular mailbox has not-indexed emails:

Get-MailboxStatistics mailboxuser | ft DisplayName,BigFunnelNotIndexedCount

To find all mailboxes that have 1 or more not-indexed emails:

Get-Mailbox -ResultSize Unlimited | Get-MailboxStatistics | ? {$_.BigFunnelNotIndexedCount -ge "1"} | ft DisplayName,BigFunnelNotIndexedCount

As stated before, a move of the mailbox to another Exchange database set the not-indexed count to 0 and emails are searchable again, but the command that should also remedy the situation, does not help:

Start-MailboxAssistant mailboxuser -AssistantName BigFunnelRetryFeederTimeBasedAssistant

The error you see in the "BigFunnelRetryFeederTimeBasedAssistant" log is:

Microsoft.Exchange.Data.Storage.AccessDeniedException: Can't update existing items in the AdminAuditLogs folder.

I still have no solution to permanently fix these issues. If you have any more ideas, put it in the comments here.

Update 30-March-2022: A solution to the problem has now been posted on the Internet: Issue the following command in the Exchange Management Shell:

New-SettingOverride -Name "Big Funnel Permanent Retry" -Component "BigFunnel" -Section "BigFunnelFailedItemsQuerySettings" -Parameters @("ExcludePermanentFailures=false") -Reason "Re-Index Messages" -MinVersion "15.2.922.7" -MaxVersion "15.2.986.22"

This should bring down the "BigFunnelNotIndexedCount" to 0 for all mailboxes after a while.

Looking at the Exchange 2019 version numbers in the command:

MinVersion: 15.2.922.7 = CU 10, no SU
MaxVersion: 15.2.986.22 = CU 11, Mar 2022 SU

Update 4-April-2022: Microsoft has now finally posted an article about this issue with the solution:

MS: Incomplete Search Results after Installing an Exchange Server 2019 Update

22 thoughts on “Microsoft Exchange 2019: Search Results are Incomplete on Server”

  1. Surely Microsoft should patch the issue better, seeing that after running the latest CU update it stop work... To move 1TB worth of users is going to take a Sh!t load of time to try and fix the search issue

    Start-MailboxAssistant -Identity "Administrator" -AssistantName BigFunnelRetryFeederTimeBasedAssistant

    This didnt work for me...

    After running

    Get-MailboxStatistics "Administrator" | fl *NotIndex*

    nothing changed...

    1. Not to mention, after moving the users the issue appears again. moving mailbox only fixes the existing issues, future search issues appear.

  2. I opened a paid case with MS in May for this issue. After weeks of checking and sessions. They closed the case, refunded my money and said its a bug that will be addressed in a future update. NO mention of when.
    Unfortunately, I cant move mailboxes for a temp fix as mine wont move anymore because the 'search' is not upto date... argghh.

  3. Hello, our Exchange 2019 stopped indexing new emails after CU11. I tried to move one mailbox to new empty database and it is working searching. Now, Im waiting to move all mailboxes to new database :-/

      1. Nothing change on your side.

        We're waiting for a fix that maybe never come ^^

        We don't manage with the mailbox migration to a new DB. But it seems that could fix the search issue. (we don't test it)

  4. @MS-Annoyance
    Is your service MS exchange search host is running ?

    In my case, I just lost three weeks of searching. Between update CU -> Start service.
    New mails are correctly indexed.

    I don't try to move to new DB. Looking for a better workaround.

    Something new in this mess ?

    1. Yes, this service is running

      We already restarted the services, and the servers as well.

      But But it did not solved the problem.

  5. I'm also getting the same error:

    Error 0x80040202 (Unknown error (0x80040202)) from StartWithParams
    + CategoryInfo : NotSpecified: (:) [Start-MailboxAssistant], RpcException
    + FullyQualifiedErrorId : [Server=,RequestId=c69eb450-77c6-4095-892f-695e06e280f4,TimeStamp=2021-12-06 9:11:37 PM] [FailureCategory=Cmdlet-RpcException] 657EE28E,Microsoft.Exchange.Mana
    + PSComputerName :

  6. @GP

    You'll habe to use ALIAS of the Mailbox in the command, abd the Parameter id CASE-SENSITIVE.


    Start-MailboxAssistant -Identity "ALIAS" -AssistantName BigFunnelRetryFeederTimeBasedAssistant

    However, this command is useless at all.
    If has never indexed any of several hundred not-indexed items.

    Even the mailbox move to another database is just a temporary solution, as newly arrived mails will also NEVER get indexed.

    Does anyone have opened a MS Ticket and may share details about an upcoming bugfix?

      1. Do you also have these error messages in

        \\\c$\Program Files\Microsoft\Exchange Server\V15\Logging\BigFunnelRetryFeederTimeBasedAssistant\*.log

        2021-12-06T13:10:06.964Z,Failures,1,BigFunnelRetryFeederTimeBasedAssistant_63649088,,"Retry Failure for mailbox 46611df4-6a96-431c-a0ec-9ba25619e29b with error : DoRetryItem failed: Microsoft.Exchange.Data.Storage.AccessDeniedException: Cannot update existing items in the Audits

      2. @Admin

        Should we hope more informations following your support case or that one is already closed without solutions

        Thanks :)

    1. Okay,
      An Uppercase was missing in the parameter.
      That said, now the command just run and do nothing : Start-MailboxAssistant -Identity "ALIAS" -AssistantName BigFunnelRetryFeederTimeBasedAssistant

      The value returned with the following command doesn't change. Get-MailboxStatistics "ALIAS" | fl bigfunnel*

      Finally, still the same errors in the bigfunnelretryfeedertimebasedassistant logs.

      Microsoft, we need your assistance.

  7. That said, I go the same issue in bigfunnelretryfeedertimebasedassistant log :Can't update existing items in the AdminAuditLogs folder

  8. Thanks.
    I've got the following error at usage of start-mailboxassistant

    Error 0x80040202 (Unknown error (0x80040202)) from StartWithParams
    + CategoryInfo : NotSpecified: (:) [Start-MailboxAssistant], RpcException

    An Idea ? :)

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