If you have a ".es" domain (or any other) where the DNS serves .com/.edu/.net domains, and you do not have an A record of the DNS server declared in your zone, your domain will have stopped working.

The reason is that Verisign has stopped publishing the glue record of these domains for non-authoritative responses. Instead it now gives a referral, and if the host is not created in its area, it is not resolved.

For further information, please go to the URL:
https://www.verisign.com/domain-name-services/domain-information-center/dns-behavior/

Please contact your hosting service provider to resolve the problem.