Looking at your other posts indicates that you're on a BES. You have questions on how to delete BES email, how to disable BES email from being pushed to your device.
That could explain how a password was set on your device. However, if you're connected to the BES, you should NOT be trying to circumvent their security policies. You may find yourself in the unemployment line.
I highly recommend searching these forums before you post. Also, please check out BlackBerry FAQ - BlackBerryFAQ