ns3.lucushost.com has no MX records.
Question and response
Question
dig ns3.lucushost.com. MX
Answer
The response has no answer records.
Authority
lucushost.com. 14400 SOA ns1.lucushost.com. noc.lucushost.com. 2026021805 3600 7200 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0