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Microsoft 365 Apps Group Policy settings

2,420 settings · 5568.1000 · 10 Aug 2026

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Microsoft Outlook 2016 › Security › Security Form Settings › Programmatic Security

Configure Outlook object model prompt when sending mail

UserNeeds changes for IntuneL_OOMSend

Supported on SUPPORTED_Windows7 (defined in the Windows templates)

What it does

This policy setting controls what happens when an untrusted program attempts to send e-mail programmatically using the Outlook object model. If you enable this policy setting, you can choose from four different options when an untrusted program attempts to send e-mail programmatically using the Outlook object model: - Prompt user - The user will be prompted to approve every access attempt. - Automatically approve - Outlook will automatically grant programmatic access requests from any program. This option can create a significant vulnerability, and is not recommended. - Automatically deny - Outlook will automatically deny programmatic access requests from any program. - Prompt user based on computer security. Outlook will only prompt users when antivirus software is out of date or not running. Important: This policy setting only applies if the ''Outlook Security Mode'' policy setting under ''Microsoft Outlook 2016\Security\Security Form Settings'' is configured to ''Use Outlook Security Group Policy.'' If you disable or do not configure this policy setting, when an untrusted application attempts to send mail programmatically, Outlook relies on the setting configured in the ''Programmatic Access'' section of the Trust Center.

What it writes

Hive
HKEY_CURRENT_USER
Registry key
software\policies\microsoft\office\16.0\outlook\security
Why it needs changes for Intune
  • Policy references a Windows supportedOn definition.
  • ADMX-INTUNE-WINDOWS-SUPPORTEDON-REFERENCE

Security baselines

Microsoft's Microsoft 365 Apps for Enterprise 2512 sets this to Enabled, in its GPO “MSFT Microsoft 365 Apps v2512 - User”.

Guard behavior
Set to “Automatically Deny” (0).

Read from the registry.pol files in the baselines' GPO backups, downloaded from Microsoft's Security Compliance Toolkit. All baselines

Options

OptionTypeRegistry valueAllowed values
Guard behaviorDefault: Prompt user based on computer security Drop-down list promptoomsend
  • Prompt User1
  • Automatically Approve2
  • Automatically Deny0
  • Prompt user based on computer security3

Configure and deploy

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

State
Options used when Enabled

Enabled · User · template defaults

Registry file (.reg)

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security]
"promptoomsend"=dword:00000003


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: Configure Outlook object model prompt when sending mail
# Name: L_OOMSend
# Scope: User
# State: Enabled
# Source: outlk16.admx

Set-RegistryValue -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security' -Name 'promptoomsend' -PropertyType 'DWord' -Value 3
  • 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_outlk16/L_OOMSend

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_outlk16/L_OOMSend</LocURI>
        </Target>
        <Data>&lt;enabled/&gt;
&lt;data id="L_OOMSend_Setting" value="3"/&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: Configure Outlook object model prompt when sending mail
# Name: L_OOMSend
# Scope: User
# State: Enabled
# Source: outlk16.admx

$isMatch = Test-RegistryValueEquals -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security' -Name 'promptoomsend' -Kind 'DWord' -Expected 3
if (-not $isMatch) {
    $reasons.Add('Value mismatch: HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security\promptoomsend') | 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: Configure Outlook object model prompt when sending mail
# Name: L_OOMSend
# Scope: User
# State: Enabled
# Source: outlk16.admx

Set-RegistryValue -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security' -Name 'promptoomsend' -PropertyType 'DWord' -Value 3

History 1 retained release

  1. 5568.100010 Aug 2026
    • Already present in the first release ChangeIntel keeps.

Template

Internal name
L_OOMSend
Namespace
outlk16.Office.Microsoft.Policies.Windows
Template file
outlk16.admx
Release
Microsoft 365 Apps 5568.1000 · file set 8be05d876aae137d…
Definition, editor controls and support

Definition

<policy Area="Security Baseline" AreaCategory="Add-ins and Extensibility" class="User" displayName="$(string.L_OOMSend)" explainText="$(string.L_OOMSend_Help)" key="software\policies\microsoft\office\16.0\outlook\security" name="L_OOMSend" presentation="$(presentation.L_OOMSend)" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_ProgrammaticSettings" />
      <supportedOn ref="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
      <elements>
        <enum id="L_OOMSend_Setting" valueName="promptoomsend">
          <item displayName="$(string.L_PromptUser)">
            <value>
              <decimal value="1" />
            </value>
          </item>
          <item displayName="$(string.L_AutoApprove)">
            <value>
              <decimal value="2" />
            </value>
          </item>
          <item displayName="$(string.L_AutoDeny)">
            <value>
              <decimal value="0" />
            </value>
          </item>
          <item displayName="$(string.L_Promptuserbasedonmachinesecurity)">
            <value>
              <decimal value="3" />
            </value>
          </item>
        </enum>
      </elements>
    </policy>

Editor controls

<presentation id="L_OOMSend" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <dropdownList defaultItem="3" noSort="true" refId="L_OOMSend_Setting">Guard behavior:</dropdownList>
      </presentation>

Supported platforms and category

outlk16.Office.Microsoft.Policies.Windows:category:L_MicrosoftOfficeOutlook
<category displayName="$(string.L_MicrosoftOfficeOutlook)" name="L_MicrosoftOfficeOutlook" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
outlk16.Office.Microsoft.Policies.Windows:category:L_ProgrammaticSettings
<category displayName="$(string.L_ProgrammaticSettings)" name="L_ProgrammaticSettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_SecurityFormsettings" />
    </category>
outlk16.Office.Microsoft.Policies.Windows:category:L_Security
<category displayName="$(string.L_Security)" name="L_Security" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeOutlook" />
    </category>
outlk16.Office.Microsoft.Policies.Windows:category:L_SecurityFormsettings
<category displayName="$(string.L_SecurityFormsettings)" name="L_SecurityFormsettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_Security" />
    </category>
outlk16.Office.Microsoft.Policies.Windows:unresolved:Microsoft.Policies.Windows:SUPPORTED_Windows7
<unresolved reference="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
outlk16.Office.Microsoft.Policies.Windows:category:L_MicrosoftOfficeOutlook
<category displayName="$(string.L_MicrosoftOfficeOutlook)" name="L_MicrosoftOfficeOutlook" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions" />
<strings><string id="outlk16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeOutlook">Microsoft Outlook 2016</string></strings>
outlk16.Office.Microsoft.Policies.Windows:category:L_ProgrammaticSettings
<category displayName="$(string.L_ProgrammaticSettings)" name="L_ProgrammaticSettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_SecurityFormsettings" />
    </category>
<strings><string id="outlk16.Office.Microsoft.Policies.Windows:L_ProgrammaticSettings">Programmatic Security</string></strings>
outlk16.Office.Microsoft.Policies.Windows:category:L_Security
<category displayName="$(string.L_Security)" name="L_Security" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_MicrosoftOfficeOutlook" />
    </category>
<strings><string id="outlk16.Office.Microsoft.Policies.Windows:L_Security">Security</string></strings>
outlk16.Office.Microsoft.Policies.Windows:category:L_SecurityFormsettings
<category displayName="$(string.L_SecurityFormsettings)" name="L_SecurityFormsettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_Security" />
    </category>
<strings><string id="outlk16.Office.Microsoft.Policies.Windows:L_SecurityFormsettings">Security Form Settings</string></strings>
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Sources read 19 Oct 07:29 UTC · 253 of 255 readable · 252 fully read · documentation 417/444 current