mx.patchwork-laboratory.com has no CNAME records.
Question and response
Question
dig mx.patchwork-laboratory.com. NS
Answer
The response has no answer records.
Authority
patchwork-laboratory.com. 3517 SOA dns.patchwork-laboratory.com. hostmaster.patchwork-laboratory.com. 1214879760 43200 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0