Can SPF or DKIM alone stop spoofing?

SPF alone doesn't stop **spoofing** because it checks the envelope sender, not the header From that recipients see. Attackers can pass **SPF** with their own domain while **spoofing** the visible From header.

DKIM alone doesn't stop **spoofing** because it signs a specific sender identity but doesn't instruct receivers what to do when messages fail. Without policy enforcement, failed **DKIM** doesn't prevent delivery.

DMARC combines both and adds enforcement. It requires **SPF** or **DKIM** to align with the header From domain and tells receivers to reject misaligned messages. Only **DMARC** with enforcement effectively prevents **domain spoofing**.