Sure, but access is different than security.  BES encrypts the data end to end - iPhone does not.  If your company is letting you view your internal documents from your corporate network on your iPhone I just pray you don't work for my bank.

I Agree with HireGoonz.   Unless your a business user that utilizes the BES server that way it was designed - to securly deliver content to your phone that lives in your enterprise, (it does more than just email folks like allowing access to sharepoint and other internal website and applications in your organization ...more