This was discovered by my sensei USSS! All the props goes to him!

So, here we go!

t is fairly simple to modify an applet, though this technique is not guaranteed to work on every Java MIDlet. One example, I believe, is O2 Mail.

Start by opening the j2me.jad file in a text editor. Usually, you can use P2K Commander to copy this file from your phone onto your PC so that you can edit it.
Look for a text string that begins with "MIDlet-Jar-RSA-SHA1:" (without the quotes), followed by a long string of random characters. Delete that entire string, including "MIDlet-Jar-RSA-SHA1:", then save the file and upload it back onto your phone. If this doesn't work, you may have to recompile the entire MIDlet with the edited file to get the applet to work.

thanks to USSS for the steps.