qmail.tokyo zone は作っていない。
1. whois
2. history
$ dig -t ns www.qmail.tokyo @ns41.cloudns.net ; <<>> DiG 9.18.1-1ubuntu1.3-Ubuntu <<>> -t ns www.qmail.tokyo @ns41.cloudns.net ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51618 ;; flags: qr aa rd; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ; COOKIE: e15788497e1a82a98ad0fd3b640824df785dbd0e38ea6582 (good) ;; QUESTION SECTION: ;www.qmail.tokyo. IN NS ;; ANSWER SECTION: www.qmail.tokyo. 3600 IN NS pns43.cloudns.net. www.qmail.tokyo. 3600 IN NS pns41.cloudns.net. www.qmail.tokyo. 3600 IN NS pns42.cloudns.net. www.qmail.tokyo. 3600 IN NS pns44.cloudns.net. ;; Query time: 1244 msec ;; SERVER: 109.201.133.196#53(ns41.cloudns.net) (UDP) ;; WHEN: Wed Mar 08 15:02:07 JST 2023 ;; MSG SIZE rcvd: 163