testsmtp.FreeBit.NET has no CNAME records.
Question and response
Question
dig testsmtp.FreeBit.NET. NS
Answer
The response has no answer records.
Authority
FreeBit.NET. 387 SOA NS21.FreeBit.NET. root.FreeBit.NET. 2026012601 14400 900 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0