out.mail.icann.org has no CNAME records.
Question and response
Question
dig out.mail.icann.org. NS
Answer
The response has no answer records.
Authority
icann.org. 1922 SOA sns.dns.icann.org. noc.dns.icann.org. 2026022793 10800 3600 1209600 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0