DNS/1/security/cookies/badについて、ここに記述してください。

返答のcookieがおかしいらしい。

$ dig mailserver.manyhost.net @ns.manyhost.net 

;; Warning: Client COOKIE mismatch

; <<>> DiG 9.11.0-P3 <<>> mailserver.manyhost.net @ns.manyhost.net
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 25190
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
; COOKIE: e8d6ec01416110015834730003000000e4e9ec01ad361001 (bad)
;; QUESTION SECTION:
;mailserver.manyhost.net.       IN      A

;; AUTHORITY SECTION:
manyhost.net.           21600   IN      SOA     ns.manyhost.net. ramzanch.gmail.com. 1487247268 36000 3600 604800 21600

;; Query time: 272 msec
;; SERVER: 85.195.97.250#53(85.195.97.250)
;; WHEN: Fri Apr 07 15:19:47 JST 2017
;; MSG SIZE  rcvd: 137