ipv4.sin01.ds.network has no MX records.
Question and response
Question
dig ipv4.sin01.ds.network. MX
Answer
The response has no answer records.
Authority
ipv4.sin01.ds.network. 3600 SOA names1.ds.network. dns.ds.network. 2023032302 7200 120 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0