Earthlink DNS servers are pulling a Verisign - instead of returning NXDOMAIN, they return a website full of ads - avoid at all costs

The unfunny thing about this issue is that it causes more harm than good, especially in this age of website phishing, mistyped domain names and general RFC non-compliance.

They even admit to it on their blog site here.

Best course of action if you are given Earthlink DNS servers to use for your internet service, is to hardcode a known good DNS server that doesn't break the rules.

Both 4.2.2.1 and 4.2.2.2 are valid DNS servers that I use in a pinch.