Which DNS record is used to specify the mail server for a domain?

Which DNS record is used to specify the mail server for a domain?

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

Answer: (C)

Mail delivery relies on DNS to tell other mail servers where to send messages for a domain. The record that designates which host handles mail for the domain is the MX record. An MX record specifies the mail exchanger’s host name and a priority value. When another mail server needs to deliver mail to someone at that domain, it queries DNS for the domain’s MX records and uses the highest-priority server first, moving to the next one if the preferred server is unavailable. The exchanger host is typically paired with an A (or AAAA) record that provides its IP address. Other DNS records aren’t about routing mail. An A record maps a domain to an IP address; an NS record lists the authoritative name servers for the zone; a TXT record stores text data—often used for SPF or DKIM checks—rather than identifying the mail server itself.

Mail delivery relies on DNS to tell other mail servers where to send messages for a domain. The record that designates which host handles mail for the domain is the MX record. An MX record specifies the mail exchanger’s host name and a priority value. When another mail server needs to deliver mail to someone at that domain, it queries DNS for the domain’s MX records and uses the highest-priority server first, moving to the next one if the preferred server is unavailable. The exchanger host is typically paired with an A (or AAAA) record that provides its IP address.

Other DNS records aren’t about routing mail. An A record maps a domain to an IP address; an NS record lists the authoritative name servers for the zone; a TXT record stores text data—often used for SPF or DKIM checks—rather than identifying the mail server itself.