Display Level 1 attachments

Information

This policy setting controls whether Outlook blocks potentially dangerous attachments designated Level 1. Outlook uses two levels of security to restrict users' 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 Outlook users can gain access to Level 1 file type attachments by first saving the attachments to disk and then opening them as with Level 2 attachments. If you disable this policy setting Level 1 attachments do not display under any circumstances. If you do not configure this policy setting Outlook completely blocks access to Level 1 files and requires users to save Level 2 files to disk before opening them.

Solution

Policy Path: Microsoft Outlook 2016\Security\Security Form Settings\Attachment Security
Policy Setting Name: Display Level 1 attachments

See Also

https://techcommunity.microsoft.com/blog/microsoft-security-baselines/security-baseline-for-m365-apps-for-enterprise-v2412/4357320

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-18(4)

Plugin: Windows

Control ID: 8a70a9e08cbb6a9f5202feeb6957d6bef2c973e2dd20c2ddc40a72815161e815