Siemens SIS has teamed up with Swiss ID quantique company to propose quantum cryptography protected key exchange over dark fiber. (See id Quantique and Siemens collaborate to commercialize Quantum Key Distribution in the Netherlands)
Quantum cryptography has the intrinsic propriety to be robust against eavesdropping. According to Heisenberg, when observing an electron, you change its spin. This makes (in theory) its interception impossible, thus extremely secure.
It is one of the first large scale commercial initiative. The offer is currently limited to Netherlands and costs about 80,000$ for a pair of boxes. Thus, it is not yet to protect your personal mails.
But, the future is coming nearer.