eus has no MX records.
Question and response
Question
dig eus. MX
Answer
The response has no answer records.
Authority
eus. 900 SOA anycast9.irondns.net. dnsmaster.corenic.org. 2603100852 7200 7200 604800 900
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0