on.themailspec.com has no MX records.
Question and response
Question
dig on.themailspec.com. MX
Answer
The response has no answer records.
Authority
on.themailspec.com. 3600 SOA pns1.cloud.sg. dnsadmin.cloud.sg. 2026020306 7200 1800 1209600 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0