Microsoft 365 Apps Group Policy settings

2,420 settings · 5568.1000 · 10 Aug 2026

1 settingCSV

Configure trusted add-ins User

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Microsoft Outlook 2016 › Security › Security Form Settings › Programmatic Security › Trusted Add-ins

Configure trusted add-ins

UserNeeds changes for IntuneL_SetTrustedAddins

Supported on SUPPORTED_Windows7 (defined in the Windows templates)

5568.1000

What it does

This policy setting can be used to specify a list of trusted add-ins that can be run without being restricted by the security measures in Outlook. If you enable this policy setting, a list of trusted add-ins and hashes is made available that you can modify by adding and removing entries. The list is empty by default. To create a new entry, enter a DLL file name in the ''Value Name'' column and the hash result in the ''Value'' column. If you disable or do not configure this policy setting, the list of trusted add-ins is empty and unused, so the recommended EC and SSLF settings do not create any usability issues. However, users who rely on add-ins that access the Outlook object model might be repeatedly prompted unless administrators enable this setting and add the add-ins to the list. Note - You can also configure Exchange Security Form settings by enabling the ''Outlook Security Mode'' setting in User Configuration\Administrative Templates\Microsoft Outlook 2016\Security\Security Form Settings\Microsoft Outlook 2016 Security and selecting ''Use Outlook Security Group Policy'' from the drop-down list.

What it writes

Hive: HKEY_CURRENT_USER
Registry key: software\policies\microsoft\office\16.0\outlook\security\trustedaddins

Why it needs changes for Intune

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

Options

Option	Type	Registry value	Allowed values
List of trusted add-ins and hashes	List of values		Name and value pairs

Configure and deploy

Choose a state and the option values; 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\outlook\security\trustedaddins]

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 trusted add-ins
# Name: L_SetTrustedAddins
# Scope: User
# State: Enabled
# Source: outlk16.admx

Clear-RegistryKeyValues -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security\trustedaddins'

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.
The generated payload is incomplete because one or more ADMX element values were not supplied: L_ListOfTrustedAddins

ADMX profile candidate (OMA-URI)

./User/Vendor/MSFT/Policy/Config/ADMX_outlk16/L_SetTrustedAddins

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 trusted add-ins
# Name: L_SetTrustedAddins
# Scope: User
# State: Enabled
# Source: outlk16.admx

$keyPath = 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security\trustedaddins'
if (Test-Path -LiteralPath $keyPath) {
    $propertyNames = (Get-Item -LiteralPath $keyPath).Property
    if ($propertyNames.Count -gt 0) {
        $reasons.Add('Key should be empty: HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security\trustedaddins') | 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 trusted add-ins
# Name: L_SetTrustedAddins
# Scope: User
# State: Enabled
# Source: outlk16.admx

Clear-RegistryKeyValues -Path 'Registry::HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security\trustedaddins'

History 1 retained release

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

Template

Internal name: L_SetTrustedAddins
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 class="User" displayName="$(string.L_SetTrustedAddins)" explainText="$(string.L_SetTrustedAddins_Help)" key="software\policies\microsoft\office\16.0\outlook\security\trustedaddins" name="L_SetTrustedAddins" presentation="$(presentation.L_SetTrustedAddins)" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_TrustedAddins" />
      <supportedOn ref="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
      <elements>
        <list explicitValue="true" id="L_ListOfTrustedAddins" />
      </elements>
    </policy>

Editor controls

<presentation id="L_SetTrustedAddins" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
        <listBox refId="L_ListOfTrustedAddins">List of trusted add-ins and hashes</listBox>
        <text>Enter the DLL filename for Value Name and the hash result for Value</text>
      </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:category:L_TrustedAddins
<category displayName="$(string.L_TrustedAddins)" name="L_TrustedAddins" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_ProgrammaticSettings" />
    </category>
outlk16.Office.Microsoft.Policies.Windows:unresolved:Microsoft.Policies.Windows:SUPPORTED_Windows7
<unresolved reference="Microsoft.Policies.Windows:SUPPORTED_Windows7" />
outlk16.Office.Microsoft.Policies.Windows:category:L_MicrosoftOfficeOutlook
<category displayName="$(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="$(string.L_SecurityFormsettings)" name="L_SecurityFormsettings" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_Security" />
    </category>
<strings><string id="outlk16.Office.Microsoft.Policies.Windows:L_SecurityFormsettings">Security Form Settings</string></strings>
outlk16.Office.Microsoft.Policies.Windows:category:L_TrustedAddins
<category displayName="$(string.L_TrustedAddins)" name="L_TrustedAddins" xmlns="http://schemas.microsoft.com/GroupPolicy/2006/07/PolicyDefinitions">
      <parentCategory ref="outlk16.Office.Microsoft.Policies.Windows:L_ProgrammaticSettings" />
    </category>
<strings><string id="outlk16.Office.Microsoft.Policies.Windows:L_TrustedAddins">Trusted Add-ins</string></strings>