smx2.interconnect.nl has no MX records.
Question and response
Question
dig smx2.interconnect.nl. MX
Answer
The response has no answer records.
Authority
interconnect.nl. 3600 SOA nsauth1.interconnect-dns.nl. postmaster.interconnect.nl. 2018060455 14400 1800 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0