mx.shopmania.net has no CNAME records.
Question and response
Question
dig mx.shopmania.net. NS
Answer
The response has no answer records.
Authority
shopmania.net. 53 SOA dns1.stabletransit.com. domains.shopmania.net. 1763720308 21600 3600 1814400 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0