bserv-mail.bserv.com has no CNAME records.
Question and response
Question
dig bserv-mail.bserv.com. NS
Answer
The response has no answer records.
Authority
bserv.com. 3600 SOA ns1b.bserv.com. root.ns1b.bserv.com. 2025091100 3600 900 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0