In order to Enterprise Activate a BlackBerry mobile device with Elephant Outlook the device must be on a BES data plan with the mobile provider.  If you are not sure which data plan your BlackBerry is on you will need to contact you mobile provider.

What is the Difference between BIS and BES?

Blackberry Internet Service (BIS)
– Self-management of inbox; integrate up to 10 e-mail accounts
– Push e-mail /every 15 min (default, dependant on ISP)
– Contacts, appointments and tasks synched manually via USB only
– Deleted Messages: from device only

Blackberry Enterprise Server (BES)
– Complete real-time wireless synchronization of email, calendar, tasks and contacts
– Security level: AES encryption
– ITS Managed Security includes password protection and auto-erase in case of theft
– Deleted Messages: Can be deleted from both device and server