curl error 7 Failed to connect to es.www.ads-software.com port 80: Connection timed out

I have the error Error en el RSS: WP HTTP Error: cURL error 7: Failed to connect to es.www.ads-software.com port 80: Connection timed out. I contact with my server and they say me that curl is working with other pages executing the comand but with www.ads-software.com not connect. They say me that could be wordpress block the server ip. I cannot install plugins, show news in dashboard, and I cannot upgrade WordPress. How I can fix this error.

Thanks!