OK. Now I think I get it! So RIM is actually playing the part of the proxy server in my earlier scenarios, and what you are paying your carrier extra for is access to RIM's network, which acts as proxy server to the rest of the internet for your BB including your copy of Software Express running on your server, and also provides encryption for everything going between RIM and your BB. Does that mean if you only use the wireless carrier's basic data package (BIS?) RIM gets cut out of the loop, and you have to use the carrier's interface between their wireless network and the internet, but that RIM's software express won't talk directly to your BB that way, but only to your BB via a connection to RIM's network? Also, that makes sense regarding hrbuckley's comment that doing it that way doesn't require every BB to have an open IP connection to the BES server, which I guess could be an issue if you were supporting thousands of BB's on that server. It also is a good way for RIM to make sure that they continue to get a cut of all the revenue...

mudtoe