Lame corporate proxies exposed

A few weeks ago I wrote about lame corporate proxy servers which mangle the HTTP request headers on behalf of their employees and customers and therefore cause them to be denied access to websites such as this one.

Statistically, our anti-spam software has been blocking access to anyone relying on the following misconfigured proxies:

Is your employer or internet service provider one of them? I guess some of you will never know, because if it is, you probably won’t be able to read this post either.