en-US office user

RPC Proxy Authentication Setting

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\Account Settings\Exchange

Description

This policy setting determines the RPC proxy authentication setting for Outlook Anywhere. If you enable this policy setting, you can specify the proxy authentication setting that Outlook uses, and this overrides any proxy authentication setting specified in Autodiscover. If you do not configure this policy setting Outlook uses the proxy server authentication specified in Autodiscover.

Registry

HKCU software\policies\microsoft\office\16.0\outlook\rpc

More options available

Options

Authentication used to connect with the proxy server:
proxyauthenticationservice enum
  • Basic -> 1
  • NTLM -> 2
  • Negotiate -> 16 (default)
  • Certificate -> 65536

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: RPC Proxy Authentication Setting
; State: Enabled
; Supported on: At least Windows Server 2008 R2 or Windows 7

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\rpc]
"proxyauthenticationservice"=dword:00000010
More formats (PowerShell, Intune, SCCM)

PowerShell

# Exported from gporais.com
# Policy: RPC Proxy Authentication Setting
# 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\rpc'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'proxyauthenticationservice' -Value 16 -Type DWord

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

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