mx01.gestiondeservidor.net has no SRV records.
Question and response
Question
dig mx01.gestiondeservidor.net. SRV
Answer
The response has no answer records.
Authority
gestiondeservidor.net. 3600 SOA dns1.gestiondeservidor.net. hostmaster.gestiondeservidor.net. 1356 10800 3600 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0