mx2.artegic.net has no CNAME records.
Question and response
Question
dig mx2.artegic.net. NS
Answer
The response has no answer records.
Authority
artegic.net. 1288 SOA ns15.artegic.net. it.artegic.net. 2026022603 36000 3600 3600000 345600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0