How do I easily send encrypted email through Outlook 2003?

I work in Health Insurance and I have to send the majority of my emails through encrypted email and it needs to be HIPAA compliant. I would prefer to use a program that works through Microsoft Outlook 2003 but am open to stand alone email programs. Let me very clear that I am looking for something VERY VERY simple! I don't want to have to get a digital certificate and I don't want to have to send the recipients pwords or keys. I just want it to encrypt and decrypt all on it's own. Up til now I have been using safe-mail.net which works ok but seems very slow and customer service is horrible if you have a problem. I have been researching for quite sometime and only found 1 programs called messagelock that will not work for my office because it requires the recipient to have to jump through hoops to retrieve the message. It needs to be easy for the people on the receiving end of the email. Please help!!!!