If we don't have BIS Plan, then the native mail client will not work even on Wifi. So, there is another best FREE alternative for mail client that works on normal data plan and wifi. It is Logic Mail, a third-party application. You can download it from here: http://logicmail.org/ota/ps: Go to the above link on your BB device. Read how to use internet(normal data plan) without BIS & BES plan.