v6.ficolo.net has no MX records.
Question and response
Question
dig v6.ficolo.net. MX
Answer
The response has no answer records.
Authority
v6.ficolo.net. 86400 SOA ns1.ficolo.net. hostmaster.ficolo.net. 2020040600 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0