Proxyrack was one of many services that provided proxy servers for anonymous access to websites. However, it is important to note that the effectiveness and reliability of such services can vary greatly, and they may have changed their services and capabilities since then. Proxy servers must be stable and fast to operate effectively. It is also important that they are reliable and do not cause problems accessing websites. I recommend visiting Proxyrack's official website, reviewing their current terms of service, and contacting their support team with specific questions about the reliability and anonymity of their service. Good information is presented on this resource https://gologin.com/best-proxy-server-services/