A Domain-Specific Lesson from the Marriott Incident

The report reviews the Marriott breach affecting ~500 million guest reservations and criticizes Marriott's use of a lookalike domain (email-marriott.com) to send notification emails; it highlights the increased phishing suspicion and deliverability/reputation risks of using a newly-registered or brand-variant domain and recommends using a subdomain of the primary domain (e.g., notification.marriott.com) to preserve trust and email reputation.