Correct Answer: B. SPF. Sender Policy Framework defines which IP addresses are authorized to send email on behalf of a domain. When a new data center with new public IP addresses is added, those IPs must be included in the domain’s SPF record. If not updated, receiving mail servers may treat the messages as spoofed and block or flag them as spam. Why The Other Options Are Incorrect A. DKIM DomainKeys Identified Mail uses cryptographic signatures to verify message integrity and domain authenticit