DomainKeys is a security protocol used to verify the authenticity of email messages and prevent email fraud. It works by digitally signing outgoing emails with a unique cryptographic key, which can then be verified by the recipient’s email server. This ensures that the email has not been tampered with or forged during transmission, providing a higher level of trust and security for email communication. DomainKeys is often used in conjunction with other email authentication methods, such as SPF and DKIM, to further enhance email security and prevent spam and phishing attacks.