ePOST is based on the Pastry
peer-to-peer overlay, which allows ePOST to scale to large numbers of
users. Since ePOST uses a peer-to-peer substrate, there are no
dedicated email servers - the function of the email server is
distributed over all of the machines in the network. However, the same
privacy level as with an existing server-based system are preserved
when using ePOST. Moreover, ePOST offers secure, authenticated
email service among ePOST users.
ePOST is designed to be backwards-compatible with existing SMTP-based email systems. In fact, ePOST users can even use their normal email clients to send and receive email, as well as send and receive email from non-ePOST users. Each user is given an email address of email@example.com, which can be used in parallel with or in place of their normal email account.