pp2011.ppsmtp.net has no CNAME records.
Question and response
Question
dig pp2011.ppsmtp.net. NS
Answer
The response has no answer records.
Authority
ppsmtp.net. 1528 SOA ns1.p68.dns.oraclecloud.net. hostmaster.ppsmtp.net. 490 3600 600 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0