mail32.self-developers.com has no CNAME records.
Question and response
Question
dig mail32.self-developers.com. NS
Answer
The response has no answer records.
Authority
self-developers.com. 848 SOA aria.ns.cloudflare.com. dns.cloudflare.com. 2395796818 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0