Which DNS record would an email server query to locate the destination mail server for a domain?

Which DNS record would an email server query to locate the destination mail server for a domain?

• A. A record
• B. MX record
• C. NS record
• D. TXT record

Answer: (B)

Email delivery relies on DNS MX records to locate the destination mail server for a domain. An MX record specifies which host is responsible for receiving mail for that domain and includes a priority so mail can be routed to the preferred server first. When a message is sent, the sender’s mail server queries DNS for the recipient domain’s MX records, then connects to the host named in the MX entry, using A or AAAA records to resolve that host to an IP address as needed. If a domain has no MX record, some systems will fall back to using the domain’s A record for delivery. Other DNS records have different roles: A records map a domain to an IP address, NS records identify the authoritative DNS servers for a zone, and TXT records hold text data (often used for SPF/DKIM), not for directing mail delivery.

Email delivery relies on DNS MX records to locate the destination mail server for a domain. An MX record specifies which host is responsible for receiving mail for that domain and includes a priority so mail can be routed to the preferred server first. When a message is sent, the sender’s mail server queries DNS for the recipient domain’s MX records, then connects to the host named in the MX entry, using A or AAAA records to resolve that host to an IP address as needed. If a domain has no MX record, some systems will fall back to using the domain’s A record for delivery. Other DNS records have different roles: A records map a domain to an IP address, NS records identify the authoritative DNS servers for a zone, and TXT records hold text data (often used for SPF/DKIM), not for directing mail delivery.