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.

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

  1. 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.

  2. 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)

  3. @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.

  4. 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 :

  5. @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.

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

  7. 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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