amon.srv.1in9.net has no MX records.
Question and response
Question
dig amon.srv.1in9.net. MX
Answer
The response has no answer records.
Authority
1in9.net. 1800 SOA arnold.ns.cloudflare.com. dns.cloudflare.com. 2396752394 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0