For me, e-mail has long been the Internet's killer application, but isn't it ready for a makeover or update?
Some things I would like to include:
-- Delayed sending of e-mail to hit people at the most appropriate time (sometimes to myself as a reminder)
-- Conversely, a smart filter that knows when to send me what sort of e-mail. This system would alert me by SMS when I had an urgent message and hold some messages until Monday if I checked my e-mail over the weekend.
What features would you add to e-mail?