MySQL Or pgSQL Drivers For UW IMAP?

Elias Israel asks: "The UW IMAP documentation comes right out and says: keeping mail in a flat file is slow and annoying. Especially if, like me, you get tons of e-mail. I've tried filtering. I've tried archiving. I've tried everything. But the sad fact is that I just have too much email and it takes too long for the IMAP server to do anything because it has to scan each mail file to find the message boundaries. With all of the development that surrounds pgSQL and MySQL, I would have thought that someone would have come up with a c-client driver for one of these freely-available databases, so that you could use something fast and indexed for the back-end of your IMAP server. Even the discussion forum on the UW IMAP information pages is strangely silent on the issue. What gives? Is anyone out there working on it? If not, why not?"