Okay !security folks. What are the recommendations on email?

I see this lovely little gem here: http://postfix.1071664.n5.nabble.com/Disabling-Anonymous-Diffie-Hellman-td67965.html

Basically the argument seems to be that if you try to be secure, you'll just force a downgrade and be entirely unsecure. This is not the kind of argument that makes me happy.

What do people think?