Cisco cache engines
Turn off http proxy service with the "no http proxy incoming" command in global config mode. This will prevent all users from arbitrarily using the cache engine as their HTTP proxy server.
More and more often, spammers are transferring spam via Squid proxies. This allows them to hide their tracks entirely, so only the host of the proxy will be reveald in the spam headers.
squid.conf should read:
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access deny all
Mailtraq bills itself as an inexpensive alternative to Microsoft Exchange that runs on ordinary Windows. Mailtraq offers a Proxy as an option to all its Mailtraq versions. If you don't set up access rules, the proxy is open to anyone to abuse
Select 'options - services' then select the properties of the HTTP proxy. In the properties there is an 'access control' tab that can be used to specify the authorized IP's.
[Append to This Answer]