Not sure I understand you completely. Are you saying that (A) you have servers in your server list, but you can't connect to them, or are you saying that (B) you don't have any servers in you server list and also can't download a server list?
If it's (B) you need to download a server list. You can do this within aMule by clicking the little button that looks like a "play" button and that is left of the server list url.
If that does not work, you can manually download the server list that I've attached to this posting (that's a current one from gruk.org), unzip it, and put it into the folder "Library/Application Support/aMule" within your home folder (you want to close aMule before you do this).
Hope this helps.
