marelay.sellbytel.es has no MX records.
Question and response
Question
dig marelay.sellbytel.es. MX
Answer
The response has no answer records.
Authority
sellbytel.es. 86400 SOA ns1.entorno.com. hostmaster.eurodns.com. 2025121500 43200 7200 1209600 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0