Which DNS record specifies the mail server responsible for accepting emails for a domain?

Which DNS record specifies the mail server responsible for accepting emails for a domain?

• A. MX
• B. A
• C. CNAME
• D. TXT

Answer: (A)

The mail delivery path for a domain is defined by MX records. An MX (mail exchanger) record identifies which server is responsible for accepting email for the domain and includes a priority so that if the primary server is unreachable, the next one can be tried. The value in an MX record is the hostname of the mail server, and that hostname must be resolvable to an IP address via an A (IPv4) or AAAA (IPv6) record. The other types don’t specify where mail should be delivered. An A record maps a hostname to an IP address, not the mail destination itself. A CNAME creates an alias for a name and isn’t suitable for directing mail flow in the way MX does. A TXT record holds arbitrary text (commonly used for SPF, DKIM, or domain verification) and does not designate the mail server responsible for accepting messages.

The mail delivery path for a domain is defined by MX records. An MX (mail exchanger) record identifies which server is responsible for accepting email for the domain and includes a priority so that if the primary server is unreachable, the next one can be tried. The value in an MX record is the hostname of the mail server, and that hostname must be resolvable to an IP address via an A (IPv4) or AAAA (IPv6) record.

The other types don’t specify where mail should be delivered. An A record maps a hostname to an IP address, not the mail destination itself. A CNAME creates an alias for a name and isn’t suitable for directing mail flow in the way MX does. A TXT record holds arbitrary text (commonly used for SPF, DKIM, or domain verification) and does not designate the mail server responsible for accepting messages.