Enable throttling for online mail indexing

ComputerIntune-readyEnableThrottlingOnlineMailboxes

Supported on Any version of Microsoft Windows with Windows Search 4.0 or later

23H2 · 1.0

What it does

When using Microsoft Office Outlook in online mode, you can enable this policy to control how fast online mail is indexed on a Microsoft Exchange server. The lower you set this policy, the lower the burden will be on the corresponding Microsoft Exchange server. The default value for this policy is 120 items per minute. To lower the burden on Microsoft Exchange servers, lower the rate of items indexed per minute. If you disable this policy, then online mail items will be indexed at the speed that the Microsoft Exchange server can support. If you set this policy to not configured, then online mail items will be indexed at the speed of 120 items per minute. This policy has no effect on mail items when using Microsoft Office Outlook in cached mode.

What it writes

Hive: HKEY_LOCAL_MACHINE
Registry key: SOFTWARE\Policies\Microsoft\Windows\Windows Search
Value name: EnableThrottlingOnlineMailboxes
When enabled: DWORD 1
When disabled: DWORD 0

In Intune

No native CSP; import the ADMX (Intune-ready).

From Microsoft's Policy CSP DDF files (DDF v2 Files, February 2026), read 18 Oct 2026.

Options

Option	Type	Registry value	Allowed values
Number of items per minuteDefault: 120	Number	`EnableThrottlingOnlineMailboxesValue`	6 to 600

Configure and deploy

Choose a state and the option values; the output below is generated from the template for exactly that.

Enabled · Computer · template defaults

Registry file (.reg)

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search]
"EnableThrottlingOnlineMailboxes"=dword:00000001
"EnableThrottlingOnlineMailboxesValue"=dword:00000078

PowerShell

$ErrorActionPreference = 'Stop'

function Set-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $PropertyType,
        [Parameter(Mandatory = $true)][object] $Value
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        New-Item -Path $Path -Force | Out-Null
    }

    New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}

function Remove-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (Test-Path -LiteralPath $Path) {
        Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
    }
}

function Clear-RegistryKeyValues {
    param(
        [Parameter(Mandatory = $true)][string] $Path
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return
    }

    foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
        Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
    }
}

# Policy: Enable throttling for online mail indexing
# Name: EnableThrottlingOnlineMailboxes
# Scope: Machine
# State: Enabled
# Source: Search.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search' -Name 'EnableThrottlingOnlineMailboxes' -PropertyType 'DWord' -Value 1

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search' -Name 'EnableThrottlingOnlineMailboxesValue' -PropertyType 'DWord' -Value 120

The OMA-URI is an inferred ADMX-backed Policy CSP candidate derived from the source ADMX file name and policy name.
Some Microsoft policies use built-in Policy CSP pages whose area names don't match the ADMX file name, so verify the candidate against Microsoft Learn before deployment.

ADMX profile candidate (OMA-URI)

./Device/Vendor/MSFT/Policy/Config/ADMX_Search/EnableThrottlingOnlineMailboxes

ADMX SyncML candidate

<SyncML xmlns="SYNCML:SYNCML1.2">
  <SyncBody>
    <Replace>
      <CmdID>1</CmdID>
      <Item>
        <Meta>
          <Format>chr</Format>
          <Type>text/plain</Type>
        </Meta>
        <Target>
          <LocURI>./Device/Vendor/MSFT/Policy/Config/ADMX_Search/EnableThrottlingOnlineMailboxes</LocURI>
        </Target>
        <Data>&lt;enabled/&gt;
&lt;data id="LimitEnableThrottlingOnlineMailboxes" value="120"/&gt;</Data>
      </Item>
    </Replace>
    <Final/>
  </SyncBody>
</SyncML>

Intune remediation scripts

Detection

$ErrorActionPreference = 'Stop'
$reasons = [System.Collections.Generic.List[string]]::new()

function Test-RegistryValueExists {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return $false
    }

    return $null -ne (Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue)
}

function Test-RegistryValueEquals {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $Kind,
        [Parameter(Mandatory = $true)][object] $Expected
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return $false
    }

    $valueObject = Get-ItemProperty -LiteralPath $Path -Name $Name -ErrorAction SilentlyContinue
    if ($null -eq $valueObject) {
        return $false
    }

    $actual = $valueObject.$Name
    switch ($Kind) {
        'String' { return [string]$actual -ceq [string]$Expected }
        'ExpandString' { return [string]$actual -ceq [string]$Expected }
        'DWord' { return [uint32]$actual -eq [uint32]$Expected }
        'QWord' { return [uint64]$actual -eq [uint64]$Expected }
        'MultiString' {
            $actualArray = @($actual)
            $expectedArray = @($Expected)
            if ($actualArray.Count -ne $expectedArray.Count) { return $false }
            for ($index = 0; $index -lt $actualArray.Count; $index++) {
                if ([string]$actualArray[$index] -cne [string]$expectedArray[$index]) { return $false }
            }
            return $true
        }
        'Binary' {
            $actualArray = [byte[]]$actual
            $expectedArray = [byte[]]$Expected
            if ($actualArray.Length -ne $expectedArray.Length) { return $false }
            for ($index = 0; $index -lt $actualArray.Length; $index++) {
                if ($actualArray[$index] -ne $expectedArray[$index]) { return $false }
            }
            return $true
        }
        default { return [string]$actual -ceq [string]$Expected }
    }
}

# Policy: Enable throttling for online mail indexing
# Name: EnableThrottlingOnlineMailboxes
# Scope: Machine
# State: Enabled
# Source: Search.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search' -Name 'EnableThrottlingOnlineMailboxes' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search\EnableThrottlingOnlineMailboxes') | Out-Null
}

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search' -Name 'EnableThrottlingOnlineMailboxesValue' -Kind 'DWord' -Expected 120
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search\EnableThrottlingOnlineMailboxesValue') | Out-Null
}

if ($reasons.Count -eq 0) {
    Write-Output 'Compliant'
    exit 0
}

$reasons | ForEach-Object { Write-Output $_ }
exit 1

Remediation

$ErrorActionPreference = 'Stop'

function Set-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name,
        [Parameter(Mandatory = $true)][string] $PropertyType,
        [Parameter(Mandatory = $true)][object] $Value
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        New-Item -Path $Path -Force | Out-Null
    }

    New-ItemProperty -LiteralPath $Path -Name $Name -PropertyType $PropertyType -Value $Value -Force | Out-Null
}

function Remove-RegistryValue {
    param(
        [Parameter(Mandatory = $true)][string] $Path,
        [Parameter(Mandatory = $true)][string] $Name
    )

    if (Test-Path -LiteralPath $Path) {
        Remove-ItemProperty -LiteralPath $Path -Name $Name -Force -ErrorAction SilentlyContinue
    }
}

function Clear-RegistryKeyValues {
    param(
        [Parameter(Mandatory = $true)][string] $Path
    )

    if (-not (Test-Path -LiteralPath $Path)) {
        return
    }

    foreach ($propertyName in (Get-Item -LiteralPath $Path).Property) {
        Remove-ItemProperty -LiteralPath $Path -Name $propertyName -Force -ErrorAction SilentlyContinue
    }
}

# Policy: Enable throttling for online mail indexing
# Name: EnableThrottlingOnlineMailboxes
# Scope: Machine
# State: Enabled
# Source: Search.admx

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search' -Name 'EnableThrottlingOnlineMailboxes' -PropertyType 'DWord' -Value 1

Set-RegistryValue -Path 'Registry::HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Windows Search' -Name 'EnableThrottlingOnlineMailboxesValue' -PropertyType 'DWord' -Value 120

History 3 retained releases

22H2 · 1.015 Jul 2024
- Already present in the first release ChangeIntel keeps.

2 later releases left it unchanged.

Template

Internal name: EnableThrottlingOnlineMailboxes
Namespace: FullArmor.Policies.3B9EA2B5_A1D1_4CD5_9EDE_75B22990BC21
Template file: Search.admx
Release: Windows 11 23H2 · 1.0 · file set d784d0ea5f14a680…

Definition, editor controls and support

Definition

<policy class="Machine" displayName="$(string.EnableThrottlingOnlineMailboxes)" explainText="$(string.ExplainEnableThrottlingOnlineMailboxes)" key="SOFTWARE\Policies\Microsoft\Windows\Windows Search" name="EnableThrottlingOnlineMailboxes" presentation="$(presentation.EnableThrottlingOnlineMailboxes)" valueName="EnableThrottlingOnlineMailboxes" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="FullArmor.Policies.3B9EA2B5_A1D1_4CD5_9EDE_75B22990BC21:Search" />
      <supportedOn ref="FullArmor.Policies.3B9EA2B5_A1D1_4CD5_9EDE_75B22990BC21:4OrLater" />
      <enabledValue>
        <decimal value="1" />
      </enabledValue>
      <disabledValue>
        <decimal value="0" />
      </disabledValue>
      <elements>
        <decimal id="LimitEnableThrottlingOnlineMailboxes" maxValue="600" minValue="6" valueName="EnableThrottlingOnlineMailboxesValue" />        
      </elements>
    </policy>

Editor controls

<presentation id="EnableThrottlingOnlineMailboxes" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <decimalTextBox defaultValue="120" refId="LimitEnableThrottlingOnlineMailboxes">Number of items per minute</decimalTextBox>
      </presentation>

Supported platforms and category

FullArmor.Policies.3B9EA2B5_A1D1_4CD5_9EDE_75B22990BC21:category:Search
<category displayName="$(string.Search)" name="Search" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.Windows:WindowsComponents" />
    </category>
FullArmor.Policies.3B9EA2B5_A1D1_4CD5_9EDE_75B22990BC21:definition:4OrLater
<definition displayName="$(string.4OrLater)" name="4OrLater" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
Microsoft.Policies.Windows:category:WindowsComponents
<category displayName="$(string.WindowsComponents)" explainText="$(string.WindowsComponents_Help)" name="WindowsComponents" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
FullArmor.Policies.3B9EA2B5_A1D1_4CD5_9EDE_75B22990BC21:category:Search
<category displayName="$(string.Search)" name="Search" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="Microsoft.Policies.Windows:WindowsComponents" />
    </category>
<strings><string id="FullArmor.Policies.3B9EA2B5_A1D1_4CD5_9EDE_75B22990BC21:Search">Search</string></strings>
FullArmor.Policies.3B9EA2B5_A1D1_4CD5_9EDE_75B22990BC21:definition:4OrLater
<definition displayName="$(string.4OrLater)" name="4OrLater" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="FullArmor.Policies.3B9EA2B5_A1D1_4CD5_9EDE_75B22990BC21:4OrLater">Any version of Microsoft Windows with Windows Search 4.0 or later</string></strings>
Microsoft.Policies.Windows:category:WindowsComponents
<category displayName="$(string.WindowsComponents)" explainText="$(string.WindowsComponents_Help)" name="WindowsComponents" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="Microsoft.Policies.Windows:WindowsComponents">Windows Components</string><string id="Microsoft.Policies.Windows:WindowsComponents_Help">Contains settings for operating system components.</string></strings>