Further, I guess pulling their users email into their system makes business sense for them, but that has always struck me as an unusual technical choice. I alw

Further, I guess pulling their users email into their system makes business sense for them, but that has always struck me as an unusual technical choice. I always thought it was so they could provide mail using a protocol that was optimized for battery life. Constantly polling a mail provider for updates is not exactly a good use of power. They couldn't really expect everyone who runs a mail server to install the necessary infrastructure to support the devices, so the next best thing is to have computers operated by RIM attached to power mains worry about collecting the email and then notify the wireless device only when there are changes. Apple uses the same basic model for their push services.