Dark Mail Technical Alliance | Encrypted end-to-end email protocol
Phil Zimmerman (PGP), Ladar Levison (Lavabit), & Team release Secure Email Protocol DIME – DIME is to SMTP as SSH is to Telnet
Full specs here: https://darkmail.info/downloads/dark-internet-mail-environment-december-2014.pdf[1] (PDF)
Full source code (libraries) here: https://github.com/lavabit/