monit04.sitelock.com has no MX records.
Question and response
Question
dig monit04.sitelock.com. MX
Answer
The response has no answer records.
Authority
sitelock.com. 180 SOA ns1.sectigodns.com. noc.sectigo.com. 2025121601 43200 3600 1209600 180
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0