One alternative to SMTP for email: Confidant Mail

[Mike Ingle]

There has been some discussion on gnupg-users about replacing SMTP for 
secure email, and how BitMessage does not scale.

There is an open source non-SMTP email system called Confidant Mail, 
which is based on GnuPG and hash table storage. The protocol conceals 
metadata (headers like From and Subject are inside the envelope) and 
uses TLS. The client has built-in support for Tor and I2P anonymity. The 
system supports unlimited length attachments (over 4GB) using a 
torrent-like blocking protocol. Messages are GPG encrypted and signed, 
and all messages are acknowledged. Key distribution is built into the 
protocol.
It's designed to scale using either DNS or a Kademlia DHT to look up 
keys. Servers are paired for high availability. The client can 
automatically configure itself from the server.

The client is available for Windows, Linux and MacOS. You can run your 
own server, or get an account on the test environment to try it out 
immediately. More information and downloads at: 
https://www.confidantmail.org

Mike Ingle <mike at confidantmail.org> d2b89e6f95e72e26e0c917d02d1847dfecfcd0c2