So that settles it for recommending Hushmail for true private communications - don't use it.
Apparently you have never been to their website. They clearly state that they will fully cooperate with law enforcement on signup. Its a mandatory checkbox on signup: I understand that Hushmail is not suitable for illegal activity and that the providers of Hushmail will cooperate fully with authorities pursuing evidence via valid legal channels. See our Security Page.
Security is a design feature, not a policy.