mx2.ukservers.net has no CNAME records.
Question and response
Question
dig mx2.ukservers.net. NS
Answer
The response has no answer records.
Authority
ukservers.net. 10764 SOA ns0.phase8.net. support.phase8.net. 2025010601 28800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0