Comprehensive and Detailed Step-by-Step Explanation:The SPF = PASS result confirms the email came from an authorized server, but DKIM = FAIL indicates the message was not properly signed with the expected DomainKeys Identified Mail (DKIM) signature. DMARC = FAIL suggests that because DKIM failed, the overall email authentication failed. This scenario is consistent with a legitimate server sending an unsigned email. References: CompTIA CySA+ All-in-One Guide (Chapter 5: Email Analysis) CompTIA CySA+ Practice Tests (Domain 1.3 Email Authentication)