ns3.opustertiary.com has no MX records.
Question and response
Question
dig ns3.opustertiary.com. MX
Answer
The response has no answer records.
Authority
opustertiary.com. 3600 SOA dns1.name-services.com. info.name-services.com. 1516982183 172800 900 1814400 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0