I've yet to find documentation describing this feature, but it is possible to use the BlackBerry Internet Service together with the BlackBerry Enterprise Server on a Blackberry device, therewith giving the user access to her corporate groupware account (Lotus Domino, Microsoft Exchange or Novell Groupwise) with BES(BlackBerry Enterprise Server) and simultaneously having her private email pushed onto the device via push mail. I've only tried this after enterprise activation, but it might as well work the other way around. For Vodafone Germany, the procedure is quite simple even though I only found it by pure chance after visiting the personal pages on their site and simply trying it out. Visit www.mobileemail.vodafone.de with your desktop browser and create a new account, entering your device PIN and the IMEI number (found in status settings of the device). From there on it is a breeze and the details fall into place easily. Choose a username which results in an email address of username at mobileemail.vodafone.de to which you can forward any messages which are then instantly pushed onto the device. In the account settings, it might be a good idea to set the Reply-To address so that your correspondents send messages back to your usual account. But this of course depends on what exactly you are trying to accomplish. Most ISP(Internet Service Providers) allow forwarding of messages to a chosen address (e.g. Google's Gmail), and there is plenty of documentation around for doing that. On the device itself, when composing a new message, a new Send using option shows up. Use Mobile email to use the BIS(BlackBerry Internet Service) and Desktop to use BES(BlackBerry Enterprise Server).