en-US office user

Configure trusted add-ins

Verified with Microsoft 365/Office 5568.1000 — updated on September 4, 2026

Microsoft 365/Office 5568.1000

Supported on: At least Windows Server 2008 R2 or Windows 7

Path in the GPO console

User Configuration\Administrative Templates\Microsoft Outlook 2016\Security\Security Form Settings\Programmatic Security\Trusted Add-ins

Description

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.

Registry

HKCU software\policies\microsoft\office\16.0\outlook\security\trustedaddins

More options available

Options

List of trusted add-ins and hashes
List (registry values) list

Export Builder

BETA

Configure the state, scope and options, then generate .reg, PowerShell, Intune and SCCM outputs — or add the setting to a multi-setting collection.

These exports write the registry — this is not a managed GPO.

.reg file

Windows Registry Editor Version 5.00

; Exported from gporais.com
; Policy: Configure trusted add-ins
; State: Enabled
; Supported on: At least Windows Server 2008 R2 or Windows 7

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security\trustedaddins]
; List values: enter one value per line in the builder UI.
More formats (PowerShell, Intune, SCCM)

PowerShell

# Exported from gporais.com
# Policy: Configure trusted add-ins
# State: Enabled
# Supported on: At least Windows Server 2008 R2 or Windows 7
# Warning: In SYSTEM context (the Intune default), HKCU targets the SYSTEM profile. Run this script using the logged-on credentials.

$path = 'HKCU:\software\policies\microsoft\office\16.0\outlook\security\trustedaddins'
New-Item -Path $path -Force | Out-Null
# List values: enter one value per line in the builder UI.

Building a multi-setting collection? Add this setting and generate combined .reg / PowerShell / GPO scripts.

Open the Builder

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