ns2.my.lu has no MX records.
Question and response
Question
dig ns2.my.lu. MX
Answer
The response has no answer records.
Authority
my.lu. 3600 SOA ns1.restena.lu. noc.restena.lu. 1771892216 14400 1800 604800 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0