en-US office user

Minimum encryption settings

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\Cryptography

Description

This policy setting allows you to set the minimum key length for an encrypted e-mail message. If you enable this policy setting, you may set the minimum key length for an encrypted e-mail message. Outlook will display a warning dialog if the user tries to send a message using an encryption key that is below the minimum encryption key value set. The user can still choose to ignore the warning and send using the encryption key originally chosen. If you disable or do not configure this policy setting, a dialog warning will be shown to the user if the user attempts to send a message using encryption. The user can still choose to ignore the warning and send using the encryption key originally chosen.

Registry

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

More options available

Options

Minimum key size (in bits):
minenckey decimal - range 0-9999 - default: 40

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: Minimum encryption settings
; State: Enabled
; Supported on: At least Windows Server 2008 R2 or Windows 7

[HKEY_CURRENT_USER\software\policies\microsoft\office\16.0\outlook\security]
"minenckey"=dword:00000028
More formats (PowerShell, Intune, SCCM)

PowerShell

# Exported from gporais.com
# Policy: Minimum encryption settings
# 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'
New-Item -Path $path -Force | Out-Null
Set-ItemProperty -Path $path -Name 'minenckey' -Value 40 -Type DWord

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

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