mail.teleson.ro has no CNAME records.
Question and response
Question
dig mail.teleson.ro. NS
Answer
The response has no answer records.
Authority
teleson.ro. 6164 SOA ns1.teleson.ro. ns2.teleson.ro. 2010050809 3600 1800 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0