From TrustTone Communications:
PrivateMail for Hotmail is the easiest email encryption solution available today. PrivateMail provides enterprise level security without any prior setup, use of passwords, or manual key/certificate exchange. Simply download, install, and activate your existing email account for private communications. You are ready to send encrypted HIPAA compliant e-mail and documents to anyone with an email address. Simple and does not install any spyware or adware.