Sandy... even if you guarantee that you have a fully encrypted session between your mail client and you mail server (whether it be a handheld or a computer), it still doesn't matter because you have positively no control over the sender's mail setup.
If the sender is delivering mail to you in clear text, which is going to be the case in an extremely high percentage of instances, then it doesn't make one bit of difference what your end is set up to do. Your end-to-end security has already failed.
Stop acting like RIM's BIS model is unsafe, full of holes, and insecure. You're just spreading FUD which you apparently wasted 4 hours and $50 on.
Give it a rest.