www138.your-server.de has no CNAME records.
Question and response
Question
dig www138.your-server.de. NS
Answer
The response has no answer records.
Authority
your-server.de. 3122 SOA ns1.your-server.de. postmaster.your-server.de. 2026030621 86400 1800 3600000 7200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0