mx3.rcs-rds.ro has no CNAME records.
Question and response
Question
dig mx3.rcs-rds.ro. NS
Answer
The response has no answer records.
Authority
rcs-rds.ro. 3600 SOA ns.rdsnet.ro. dns-adm.rdsnet.ro. 2026022602 1200 180 3600000 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0