Blackberry mobile phones are the absolute best mobile phone for business productivity if and ONLY IF they are connected to a Blackberry Enterprise Server.
Most cell phone companies connect the Blackberry to the Blackberry Internet Service for business clients to send and receive business email. It is such a shame as their is so much more functionality that is available for a Blackberry.
Blackberry Enterprise Service provides incredible speed of email delivery, and synchronizes subfolders of your Inbox if desired. Every sent item on your mobile phone can end up in your Sent Items folder in Outlook. It also synchronizes your Calendar, Contacts, Tasks, Notes and all your Blackberry phone preferences.
If you happen to lose or break your existing Blackberry phone, simply reconnecting the new Blackberry to the Blackberry Enterprise server restores all the information that was on your old phone to the new phone in minutes.