secondary.interactivedns.com has no MX records.
Question and response
Question
dig secondary.interactivedns.com. MX
Answer
The response has no answer records.
Authority
interactivedns.com. 300 SOA primary.interactivedns.com. nettigritty.nettigritty.com. 2026030302 3600 7200 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0