Action to demote an EMail Level 1 attachment to Level 2 must be configured.

Outlook uses two levels of security to restrict access to files attached to email 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 users can demote Level 1 files to Level 2, they will be able to access potentially dangerous files after saving them to disk, which could allow malicious code to affect their computers or compromise the security of sensitive information.