awswww1.ecomark.jp has no MX records.
Question and response
Question
dig awswww1.ecomark.jp. MX
Answer
The response has no answer records.
Authority
ecomark.jp. 300 SOA 01.dnsv.jp. hostmaster.dnsv.jp. 1736242011 3600 900 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0