biblioteca.feeye.uncu.edu.ar has no MX records.
Question and response
Question
dig biblioteca.feeye.uncu.edu.ar. MX
Answer
biblioteca.feeye.uncu.edu.ar. 5 CNAME bdigital.uncu.edu.ar.
Authority
bdigital.uncu.edu.ar. 10800 SOA raiz.uncu.edu.ar. cit-servidores.uncu.edu.ar. 2025053001 28800 7200 2419200 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0