mail?

So we have in Haskell quite a few consumer applications

1. revision control system
2. text editor
3. window manager

When's the mail client coming? I'm asking this in the random speculative sense, not in the "gimme a Haskell mail client now" sense. What would a Haskell mail client look like? I'm guessing that plugins will play a nice role, extensibility and all. Being able to handle really large mailboxes (a big "archive" folder) would be nice. Perhaps Sup would be good inspiration. Come to think of it, maybe the client should be implemented in Cat, just for the name...