There are two main BlackBerry smartphone mobile connectivity options, and they are quite different. The first is the BlackBerry Internet Service, in which your mobile carrier acts as a liaison between your email and your BlackBerry smartphone. The second option is to use a BlackBerry Enterprise Server, which directly links your wireless device to your email, contacts, calendars and business applications— virtually automatically and almost instantly. If you’re using a BlackBerry smartphone solely for personal email, then a BlackBerry Internet Service account is all you need, and you can stop reading here. But if you’re a business user and are only using BlackBerry Internet Service, you’re leaving lots of important functionality unused.