ns3.dnsowl.com has no MX records.
Question and response
Question
dig ns3.dnsowl.com. MX
Answer
The response has no answer records.
Authority
dnsowl.com. 172800 SOA ns1.dnsowl.com. hostmaster.dnsowl.com. 1772638922 7200 1800 1209600 600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0