What email security method utilizes authentication methods and encryption features to manage messages effectively after a whaling attack?

The chosen answer focuses on DMARC, which stands for Domain-based Message Authentication, Reporting, and Conformance. This method enhances email security by combining two existing authentication techniques—SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail). DMARC allows organizations to set policies on how email receivers should handle unauthenticated messages, providing a mechanism to report back on mail that fails authentication checks.

In the context of managing messages effectively after a whaling attack, which is a targeted attempt to steal sensitive information through email, DMARC helps in two significant ways. First, it provides a way to ensure that only legitimate emails are being sent from the organization’s domain, minimizing the risk of spoofed emails that could mislead recipients. Second, it offers a feedback loop that can notify the organization about messages that failed the authentication checks, allowing for ongoing monitoring and response to potential threats.

The other options, while relevant to email security, do not provide the same comprehensive approach. SPF alone helps verify sender IP addresses but does not dictate handling rules for failed messages. Transport Layer Security (TLS) is focused on securing the transmission of email rather than authentication, and S/MIME (Secure/Multipurpose Internet Mail Extensions) is primarily used for encryption