DKIM, SPF (Sender Policy Framework), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) are all email authentication methods. While SPF checks if the sender's IP address is authorized to send emails on behalf of the domain, DKIM verifies the integrity and authenticity of the email content. DMARC builds upon both SPF and DKIM by providing instructions to receiving mail servers on how to handle emails that fail these checks. Together, these methods provide a comprehensive solution for securing email communications.