smtp2.patt.net has no CNAME records.
Question and response
Question
dig smtp2.patt.net. NS
Answer
The response has no answer records.
Authority
patt.net. 2181 SOA ns.owe.de. hostmaster.owe.de. 2024112805 10800 3600 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0