_acme-challenge.aciglobal.com has no MX records.
Question and response
Question
dig aciglobal.com.acme.neonova.net. MX
Answer
The response has no answer records.
Authority
acme.neonova.net. 300 SOA acme.neonova.net. ops.neonova.net. 66803 86400 3600 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0