Allow users to demote attachments to Level 2

Information

This policy setting controls whether Outlook users can demote attachments to Level 2 by using a registry key, which will allow them to save files to disk and open them from that location. Outlook uses two levels of security to restrict access to files attached to e-mail messages or other items. Files with specific extensions can be categorized as Level 1 (users cannot view the file) or Level 2 (users can open the file after saving it to disk). Users can freely open files of types that are not categorized as Level 1 or Level 2.
If you enable this policy setting, users can create a list of Level 1 file types to demote to Level 2 by adding the file types to the following registry key: HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Security\Level1Remove.
If you disable or do not configure this policy setting, users cannot demote level 1 attachments to level 2, and the HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Security\Level1Remove registry key has no effect.

Solution

Policy Path: Microsoft Outlook 2016\Security\Security Form Settings\Attachment Security
Policy Setting Name: Allow users to demote attachments to Level 2

See Also

https://techcommunity.microsoft.com/t5/microsoft-security-baselines/security-baseline-for-microsoft-365-apps-for-enterprise-v2112/ba-p/3038172

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6b.

Plugin: Windows

Control ID: 71040a24c120394e4e4b715f5dcac7e7a2b5fa2171f1741b21a1d5d38b5ddb64