mercury.ubs.com has no CNAME records.
Question and response
Question
dig mercury.ubs.com. NS
Answer
The response has no answer records.
Authority
ubs.com. 300 SOA cnsi-rzud-6601.core.ubs.net. ncc-internet.ubs.com. 2009382765 900 90 604800 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0