It is main.EmpireMinecraft.com but right now Minecraft.net is having issues, so it is hard to login to any server right now. We're just waiting it out.
Is that still in effect? I just joined on this website and have tried a few times to log into the server which has 40 people online. Did I miss something somewhere? A new player login pass code somewhere. To be honest I'll probably find how to play as soon as I post this reply...
Guess what? By the power of grey skull... it took me 20 seconds to find the right forum post as to whats wrong, and this was the answer http://session.minecraft.net/
at least that's my best guess, I don't get why 24 people are still online, but then I'm newish to this game.