Use Protected View for attachments received from internal senders

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

Registry

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

Value name: markinternalasunsafe

Enabled: markinternalasunsafe = 1

Disabled: markinternalasunsafe = 0

Description

This policy setting allows you to determine if attachments received from senders within your organization open in Protected View. This setting only applies to Outlook accounts setup to use an Exchange server. If you enable this policy setting, attachments received from senders within your organization open in Protected View. If you disable or do not configure this policy setting, attachments received from senders within your organization do not open in Protected View.