If you change Blackberrys for any reason like an upgrade or warranty replacement and you are using the Blackbery Web Client, you will then need to change your web settings to start receiving mail again. Each Blackberry has a unique PIN and IMEI number to identify the device on the network so your settings need to reflect the appropriate numbers. So if you were going to change Blackberrys you will need to do the following:
1. Log in to your BlackBerry Internet Service account.
2. On the navigation bar at the top of the screen, click Profile.
3. On the Profile page, click Change Handheld.
4. On the Change Handheld page, the handheld’s current PIN appears in the PIN field. To change it, delete the number and enter your new PIN number.
5. Enter your ESN/IMEI in the ESN/IMEI field.
Note: Both the PIN and ESN/IMEI appear on the handheld in Options –> Status.
6. Click Submit. Your PIN is updated.
Don’t forget this is a carrier configurable option. Not all carriers allow you to do this.