Wait, you're THAT jgrahamc?! Whoa, small world. I nearly invited you to speak in Japan about POPFile and OSS at the technology incubator that was my ex-ex-day job, but our budget fell through. As far as I know our not-quite-ready-for-primetime POPFile/Outlook integration is still protecting a few hundred desktops next to a rice field.
Whoa. Are you talking about QuickPOPFile?
I would have happily come to Japan and spoken, I've been there before and always loved the place.
QuickPOPFile was not quite us, but the general idea to make it useful for non-technical folks was similar. (We were going to aggregate filtering across an organization, on the assumption that most folks couldn't be bothered to train emails. Turns out this is easier to do if you are Google than if you want to run a parallel mail infrastructure alongside the one that actually delivers mail.)
POPFile is awesome. Definitely one of the most useful email apps I've ever used. Thanks for all your work behind it.
POPFile grew from POP only to lots of other protocols and many, many people still use it.