Well, then you need to go into your email configuration on your device and change what is stored there to the password you changed to. Your email credentials are stored on your device, so when you change them on the server, you must also change them wherever they are stored in this manner.
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.