ns2.desec.org has no MX records.
Question and response
Question
dig ns2.desec.org. MX
Answer
The response has no answer records.
Authority
desec.org. 300 SOA get.desec.io. get.desec.io. 2025114331 86400 3600 2419200 3600
Additional
. 0 OPT ; payload 1400, xrcode 0, version 0, flags 0