mx.ipacs.pro has no CNAME records.
Question and response
Question
dig mx.ipacs.pro. NS
Answer
The response has no answer records.
Authority
ipacs.pro. 5449 SOA ns1.gandi.net. hostmaster.gandi.net. 1771661109 10800 3600 604800 10800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0