smtp.tookmail.com has no CNAME records.
Question and response
Question
dig smtp.tookmail.com. NS
Answer
The response has no answer records.
Authority
tookmail.com. 300 SOA x.ns.joker.com. hostmaster.joker.com. 2024110687 14400 3600 1209600 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0