mail.reylounge.de has no CNAME records.
Question and response
Question
dig mail.reylounge.de. NS
Answer
The response has no answer records.
Authority
reylounge.de. 3600 SOA ns1.contabo.net. hostmaster.contabo.de. 1772829812 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0