[...]
    server {
        listen       80;
        server_name  localhost;
        root   /usr/local/www/roundcube;
        index index.php index.html index.htm;

        # scripts de PHP
        location ~ \.php$ {
            fastcgi_param PATH_INFO $fastcgi_path_info;
            fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
            fastcgi_pass   127.0.0.1:9000;
            fastcgi_index  index.php;
            include        fastcgi_params;
        }
    }
[...]