Nginx conflicting server name

Hi, how are you?

Excuse me, I forgot to translate.
running nginx -t the following message appears:
nginx: [warn] conflicting server name “domain.cl” on 0.0.0.0:80, ignored
nginx: [warn] conflicting server name “mail.domain.cl” on 0.0.0.0:80, ignored

This appears with the names of all the hosted domains, twice each.
At the end:
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

It’s a problem? or it can be like this. I am trying to serve js files with node and express.