ns4.ithnet.com has no MX records.
Question and response
Question
dig ns4.ithnet.com. MX
Answer
The response has no answer records.
Authority
ithnet.com. 3600 SOA ns.ithnet.com. hostmaster.ithnet.com. 2026020402 9000 1800 650000 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0