smtp.setarnet.aw has no CNAME records.
Question and response
Question
dig smtp.setarnet.aw. NS
Answer
The response has no answer records.
Authority
setarnet.aw. 144 SOA intns.setarnet.aw. hostmaster.setarnet.aw. 2026030405 1800 1800 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0