imap.hostbrid.com has no CNAME records.
Question and response
Question
dig imap.hostbrid.com. NS
Answer
The response has no answer records.
Authority
hostbrid.com. 1469 SOA ns1.hostbrid.com. admin.hostbrid.com. 2026021821 3600 900 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0