So, I grabbed instructions for setting up exim and UW-IMAP on cygwin. Once I launched the cygwin installer, I figured I'd just grab most everything except what I was already running and be done with it. A couple of hours later, it was done installing and I went to connect.
Now, it should be noted that I did not choose to install/uninstall/reinstall or otherwise modify the OpenSSH portion. However, the new setup managed to break ssh access completely. It was failing to find /bin/switch, which indicated a path problem. OK, I guess it's time to uninstall the OpenSSH setup I had and get a fresh one from cygwin.
Enter what turned out to be some of the nicest instructions I've seen in a long time. They aren't flashy, are in plain English and just covered the necessary settings and configuration. They actually covered everything that I needed to do, it all worked and 5 minutes later, I was able to ssh back into the server.
So, if you've wanted to, for instance, block off most ports at your firewall, but still get access to your home machine from the road or office, give this a shot.