mail.streifling.com has no CNAME records.
Question and response
Question
dig mail.streifling.com. NS
Answer
The response has no answer records.
Authority
streifling.com. 3588 SOA ns3.epik.com. support.epik.com. 2026021801 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0