rdns.distributel.net has no MX records.
Question and response
Question
dig rdns.distributel.net. MX
Answer
The response has no answer records.
Authority
rdns.distributel.net. 2560 SOA ns1.distributel.net. noc.distributel.net. 2024030100 16384 2048 1048576 2560
Additional
. 0 OPT ; payload 512, xrcode 0, version 0, flags 0