Wirelessly posted (8700g: BlackBerry8800/4.2.1 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)
Use the BIS setup (BlackBerry Internet Service). Details at this link, scroll down to "how do I add or delete my BIS".
http://www.blackberryfaq.com/index.php/Main_Page
Good luck.