## page was renamed from NULL_MX
NULL_MXについて、ここに記述してください。

 A "Null MX" No Service Resource Record for Domains That Accept No Mail

https://tools.ietf.org/html/rfc7505

{{{
%dnsq mx qmail.jp a.ns.qmail.jp
15 qmail.jp:
76 bytes, 1+1+1+1 records, response, authoritative, noerror
query: 15 qmail.jp
answer: qmail.jp 86400 MX 0 .
authority: qmail.jp 86400 NS a.ns.qmail.jp
additional: a.ns.qmail.jp 86400 A 14.192.44.5
}}}


https://tools.ietf.org/html/rfc2782