The Secure Mail project hopes to establish a secure e-mail infrastructure for LCS. Why don't people at LCS use secure e-mail? Would a secure e-mail infrastructure enable people to get things done that they currently can not?
We wish to transparently provide end-to-end confidentiality and authentication for e-mail. The recipient must take responsibility for storing mail securely after it has been read. The key requirements are usability and transparency. These are probably the reason why secure mail has not been more widely deployed.
Also, let's not forget Why Cryptography is Harder Than it Looks (Bruce Schneier).
Much of the software needed has probably already been implemented so the task is mainly to find, categorize, document and deploy existing software.