mx1-s1-nd.perf1.net has no MX records.
Question and response
Question
dig mx1-s1-nd.perf1.net. MX
Answer
The response has no answer records.
Authority
perf1.net. 7200 SOA nsa.perf1.fr. technical.nameshield.net. 2026022601 28800 7200 604800 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0