Configure Simple MAPI sending prompt: registry value promptsimplemapisendUserHKCU\software\policies\microsoft\office\16.0\outlook\security

Policy ID: L_SimpleMapiSend
Scope: User Configuration
Supported on: At least Windows Server 2008 R2 or Windows 7
Source: Microsoft 365 Apps / Office Administrative Templates (version 5568.1000)
Category: Microsoft Outlook 2016 › Security › Security Form Settings › Programmatic Security

Registry

promptsimplemapisend

REG_DWORDUser

HKCU\software\policies\microsoft\office\16.0\outlook\security Current key

Enabled value: Depends on the option value
Element: Guard behavior:

Options
Item	Stored value
Prompt User	1
Automatically Approve	2
Automatically Deny	0

Apply with .reg · CMD · PowerShell

.reg

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security]

; Options (use only one)
; Prompt User
"promptsimplemapisend"=dword:00000001
; Automatically Approve
"promptsimplemapisend"=dword:00000002
; Automatically Deny
"promptsimplemapisend"=dword:00000000

CMD

:: Options (use only one)

:: Prompt User
reg add "HKCU\software\policies\microsoft\office\16.0\outlook\security" /v "promptsimplemapisend" /t REG_DWORD /d 1 /f
:: Automatically Approve
reg add "HKCU\software\policies\microsoft\office\16.0\outlook\security" /v "promptsimplemapisend" /t REG_DWORD /d 2 /f
:: Automatically Deny
reg add "HKCU\software\policies\microsoft\office\16.0\outlook\security" /v "promptsimplemapisend" /t REG_DWORD /d 0 /f

PowerShell

# Common: create the key
New-Item -Path 'HKCU:\software\policies\microsoft\office\16.0\outlook\security' -Force | Out-Null

# Options (use only one)
# Prompt User
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\outlook\security' -Name 'promptsimplemapisend' -PropertyType DWord -Value 1 -Force | Out-Null
# Automatically Approve
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\outlook\security' -Name 'promptsimplemapisend' -PropertyType DWord -Value 2 -Force | Out-Null
# Automatically Deny
New-ItemProperty -Path 'HKCU:\software\policies\microsoft\office\16.0\outlook\security' -Name 'promptsimplemapisend' -PropertyType DWord -Value 0 -Force | Out-Null