NNCP has modern security: full end-to-end encryption, onion routing, cryptographic signatures, and so forth. It also can use anything from synchronized folders to USB sticks as carriers, in addition to the regular Internet.<p>It turns out that all the most common MTAs (Mail Transport Agents; mail servers) still have the hooks for UUCP. So NNCPNET takes advantage of that, substitutes in NNCP plus some routing and verification logic, and poof: instant email network.