mta-183.0.ncdelivery04.com has no MX records.
Question and response
Question
dig mta-183.0.ncdelivery04.com. MX
Answer
The response has no answer records.
Authority
ncdelivery04.com. 86400 SOA ns1.ncdelivery04.com. Postmaster.ncdelivery04.com. 639748623 10800 3600 172800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0