one has no MX records.
Question and response
Question
dig one. MX
Answer
The response has no answer records.
Authority
one. 900 SOA a.nic.one. admin.tldns.godaddy. 1771990285 1800 300 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0