DMARC Explained: How to Stop Attackers From Impersonating Your Domain
Email is still the most common way attacks begin. Phishing, business email compromise, and brand impersonation all rely on one simple weakness: by default, anyone can send an email that claims to come from your domain. The protocol that email runs on was never built to verify who a sender really is, so a criminal can forge the "From" address to look exactly like it came from your company, and the receiving mail server has no built-in way to know the difference. That is the gap attackers exploit, and it is the gap DMARC was designed to close.