relay.mailwish.com has no CNAME records.
Question and response
Question
dig relay.mailwish.com. NS
Answer
The response has no answer records.
Authority
mailwish.com. 1800 SOA ivan.ns.cloudflare.com. dns.cloudflare.com. 2397846735 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0