The analogy works to some extent, but it is a gross oversimplifications in most regards. But yeah, keeping up with maintaining a small mail server if you expect not to continually end up in SPAM is a royal pain.

Will be interesting to see how it develops. Could see a movement towards RBL type block lists, but with the lack of tools available at the moment I think most admins are going to end up having to take some pretty drastic actions at times.