Open Proxy Explained

What is an open proxy?

An open proxy is a server that acts as an open relay but through ports other than 25; open proxies provide surrogate (proxy) communication ability to other servers through ports not reserved for normal use.

Why should I secure my open proxy?

This is a similar situation to running an open relay: you are allowing non-paying users on your system to have free rein of your resources. Most of the open proxy server owners we've worked with weren't aware of their vulnerabilities.

How do I secure my open proxy?

You can either disable connections to the open ports in question or establish an 'access control list' (ACL) for that system, which will allow only authorised users to connect to those ports.

Which ports am I vulnerable on?

When you initiate a database search for your IP, the email we generate and send to 'postmaster@IPaddress' and 'root@IPaddress' will list all the ports we have found to be available for unrestricted use.

I've secured my server ... how do I get unblocked?

We have a process that goes through our database of open proxies and tests them every 24 hours. If we find that our attempts to use your open ports are unsuccessful, we will change the status of your server from open to closed. We will then remove your IP from our block list and push the changes into production. These processes are automated, and 'unblocks' generally occur in about 24 hours.