If you receive the following error or bounce back:

“is blocked by EarthLink. Go to earthlink.net/block for details”

This is because your IP number is on EarthLink’s private IP blacklist.  EarthLink does not publish a database in which you can query against, so unfortunately the only way to find out if you’re listed is to receive the above bounce back. As the error message states, you should visit their website at earthlink.net/block to request removal.