smtp.telfy.com has no MX records.
Question and response
Question
dig smtp.telfy.com. MX
Answer
The response has no answer records.
Authority
telfy.com. 86400 SOA ns1.telfy.com. servidores.telfy.com. 2026022202 3600 7200 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0