MX, TXT, NS e SOA

MX, TXT, NS, and SOA

MX records identify mail servers, TXT records carry text interpreted by other protocols, NS records identify name servers, and SOA records contain zone-level information such as the serial number and timers.

MX is not the server address

example.test. 300 IN MX 10 mail.example.test.
mail.example.test. 300 IN A 192.0.2.25

The MX target is a host name plus a preference. The mail system resolves that target to A or AAAA records; an IP address does not go directly in the MX target field. A lower MX preference number is normally tried first.

TXT is not one universal format. SPF, DKIM, DMARC, and ownership checks each define their own syntax and rules. When reading a TXT value, identify the protocol that consumes it.

Check your understanding

Choose the best answer. This quiz runs locally and sends no DNS queries to real domains.