mail.jits.rocks has no CNAME records.
Question and response
Question
dig mail.jits.rocks. NS
Answer
The response has no answer records.
Authority
jits.rocks. 4203 SOA ns.jits.rocks. admin.jits.rocks. 78 14400 3600 604800 60
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0