External sender warnings SHALL be implemented.

Why This Matters

External sender warnings help protect users from phishing attacks and spoofed emails by clearly marking messages from outside your organization. Without these warnings, users may inadvertently trust and interact with malicious emails that appear to come from internal senders. Implementing external sender warnings reduces the risk of credential theft, malware infection, and data breaches.

What Aether365 Checks

Aether365 verifies whether Exchange Online mail flow rules or user interface settings are configured to display an external sender warning for all messages originating from outside your organization. This check appears on your Aether365 dashboard under the microsoft-365 compliance category.