Do not compress the inlined images inserted in Outlook

UserNeeds changes for IntuneL_DoNotCompressInlinedImagesInOutlook

Supported on SUPPORTED_Windows7 (defined in the Windows templates)

5568.1000

What it does

This policy setting allows you to disable compression on inlined images in Outlook. If you enable this policy setting, Outlook won't compress inlined images in the message. If you disable or don't configure this policy setting, inlined images would be compressed. Note: This policy setting only applies to subscription versions of Office, such as Microsoft 365 Apps for enterprise.

What it writes

Hive: HKEY_CURRENT_USER
Registry key: software\policies\microsoft\office\16.0\common\mailsettings
Value name: outlookdonotcompressimages
When enabled: DWORD 1
When disabled: DWORD 0

Why it needs changes for Intune

Policy references a Windows supportedOn definition.
ADMX-INTUNE-WINDOWS-SUPPORTEDON-REFERENCE

Configure and deploy

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

Enabled · User · template defaults

Registry file (.reg)

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\common\mailsettings]
"outlookdonotcompressimages"=dword:00000001

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: Do not compress the inlined images inserted in Outlook
# Name: L_DoNotCompressInlinedImagesInOutlook
# Scope: User
# State: Enabled
# Source: word16.admx

Set-RegistryValue -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\common\mailsettings' -Name 'outlookdonotcompressimages' -PropertyType 'DWord' -Value 1

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)

./User/Vendor/MSFT/Policy/Config/ADMX_word16/L_DoNotCompressInlinedImagesInOutlook

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>./User/Vendor/MSFT/Policy/Config/ADMX_word16/L_DoNotCompressInlinedImagesInOutlook</LocURI>
        </Target>
        <Data>&lt;enabled/&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: Do not compress the inlined images inserted in Outlook
# Name: L_DoNotCompressInlinedImagesInOutlook
# Scope: User
# State: Enabled
# Source: word16.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\common\mailsettings' -Name 'outlookdonotcompressimages' -Kind 'DWord' -Expected 1
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\common\mailsettings\outlookdonotcompressimages') | 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: Do not compress the inlined images inserted in Outlook
# Name: L_DoNotCompressInlinedImagesInOutlook
# Scope: User
# State: Enabled
# Source: word16.admx

Set-RegistryValue -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\common\mailsettings' -Name 'outlookdonotcompressimages' -PropertyType 'DWord' -Value 1

History 1 retained release

5568.100010 Aug 2026
- Already present in the first release ChangeIntel keeps.

Template

Internal name: L_DoNotCompressInlinedImagesInOutlook
Namespace: word16.Office.Microsoft.Policies.Windows
Template file: word16.admx
Release: Microsoft 365 Apps 5568.1000 · file set 8be05d876aae137d…

Definition, editor controls and support

Definition

<policy class="User" displayName="$(string.L_DoNotCompressInlinedImagesInOutlookTitle)" explainText="$(string.L_DoNotCompressInlinedImagesInOutlookExplain)" key="software\policies\microsoft\office\16.0\common\mailsettings" name="L_DoNotCompressInlinedImagesInOutlook" valueName="outlookdonotcompressimages" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="word16.Office.Microsoft.Policies.Windows:L_EmailOptions" />
      <supportedOn ref="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
      <enabledValue>
        <decimal value="1" />
      </enabledValue>
      <disabledValue>
        <decimal value="0" />
      </disabledValue>
    </policy>

Editor controls

Supported platforms and category

word16.Office.Microsoft.Policies.Windows:category:L_Advanced
<category displayName="$(string.L_Advanced)" name="L_Advanced" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="word16.Office.Microsoft.Policies.Windows:L_WordOptions" />
    </category>
word16.Office.Microsoft.Policies.Windows:category:L_EmailOptions
<category displayName="$(string.L_EmailOptions)" name="L_EmailOptions" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="word16.Office.Microsoft.Policies.Windows:L_Advanced" />
    </category>
word16.Office.Microsoft.Policies.Windows:category:L_MicrosoftOfficeWord
<category displayName="$(string.L_MicrosoftOfficeWord)" name="L_MicrosoftOfficeWord" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
word16.Office.Microsoft.Policies.Windows:category:L_WordOptions
<category displayName="$(string.L_WordOptions)" name="L_WordOptions" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="word16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeWord" />
    </category>
word16.Office.Microsoft.Policies.Windows:unresolved:Microsoft.Policies.Windows:SUPPORTED_Windows7
<unresolved reference="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
word16.Office.Microsoft.Policies.Windows:category:L_Advanced
<category displayName="$(string.L_Advanced)" name="L_Advanced" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="word16.Office.Microsoft.Policies.Windows:L_WordOptions" />
    </category>
<strings><string id="word16.Office.Microsoft.Policies.Windows:L_Advanced">Advanced</string></strings>
word16.Office.Microsoft.Policies.Windows:category:L_EmailOptions
<category displayName="$(string.L_EmailOptions)" name="L_EmailOptions" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="word16.Office.Microsoft.Policies.Windows:L_Advanced" />
    </category>
<strings><string id="word16.Office.Microsoft.Policies.Windows:L_EmailOptions">E-mail Options</string></strings>
word16.Office.Microsoft.Policies.Windows:category:L_MicrosoftOfficeWord
<category displayName="$(string.L_MicrosoftOfficeWord)" name="L_MicrosoftOfficeWord" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="word16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeWord">Microsoft Word 2016</string></strings>
word16.Office.Microsoft.Policies.Windows:category:L_WordOptions
<category displayName="$(string.L_WordOptions)" name="L_WordOptions" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="word16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeWord" />
    </category>
<strings><string id="word16.Office.Microsoft.Policies.Windows:L_WordOptions">Word Options</string></strings>