I doubt it, the only thing affected by the is telepathy which is the backend for the IM application, hence things like gtalk, jabber, msn will not work. every other thing should work fine and use the system-wide proxy settings for the N900. On the N810 the mailing application works very fine even while you are behind a a network proxy. Hence I think mail for exchange should be fine. But someone with an N900 will be in a better position to confirm.