Reading a DNS lookup result

A records represent IPv4 addresses and AAAA records represent IPv6 addresses. MX records identify mail servers and priorities; NS records identify authoritative name servers. TXT records contain text used for several kinds of configuration.

TTL gives the permitted cache lifetime in seconds. Resolvers may return different data shortly after a change. This site’s lookup is not a global propagation test from distributed locations.

NXDOMAIN is a DNS response stating that the name does not exist. Timeouts and network errors are different. A failed request alone does not establish that a domain is missing or its mail configuration is invalid.