> Email does not fit that medium.
Why not?
Email can be implemented in a global p2p file database. Every "email" simply adds another file. Privacy can be ensured with encryption (as long as the encryption is not broken, at least). See existing Freenet message boards for an example.
It may not be Internet RFC821/822 (and subsequent standards) Email, but it is email.
What part of this will not fit the Freenet model?