Got my balking mail running. Turns out my ISP was blocking port 2525, but not port 25. Does this make sense to anyone? No? I didn't think so.
Got my shoutcast server up and running. Whee! So, if anyone wants to listen to what I'm listening to at the moment, tune in to http://doubt72.dyndns.org:8000/ and listen to it in all of its 96kbps glory (I actually have enough bandwidth that I might up it up a bit, or open more connections if anyone actually listens to it).
My cat, though, is not adjusting too well to the move.