Actually already did that, and i got the next answere:

[root@proxy-n1 ~]# curl -H "Auth-Method: plain" \
> -H "Auth-User: ricardo.carrillo" \
> -H "Auth-Pass: r3dh4t" \
> -H "Auth-Protocol: imap" \
> -H "Auth-Login-Attempt: 1" \
> -i http://192.168.122.170:80/correo-proxy-auth/index.php
HTTP/1.1 500 Internal Server Error
Server: nginx/1.6.2
Date: Wed, 11 Mar 2015 23:18:54 GMT
Content-Type: text/html
Transfer-Encoding: chunked
Connection: keep-alive
X-Powered-By: PHP/5.4.16

but the error logs are not very descriptive.