An MX (Mail Exchange) record specifies the mail server responsible for receiving email for a domain. * Why Not A (CNAME): CNAME is used for domain aliasing, not for email delivery. * Why Not B (SRV): SRV records are used to locate specific services, not mail servers. * Why Not D (SOA): SOA records provide domain information but do not handle email. CompTIA A+ Exam Reference: Core 1 (220-1101), Section 2.6, DNS record types.