[Freedombox-discuss] Idea for cross freedombox email system not leaking metadata

[Sam Hartman]

What you propose with exim and hidden addresses ought to be relatively
simple to set up.
You'd want to take a careful look at your DNS traffic to make sure
you're not leaking things there both at the email client layer and at
the exim layer.
In particular, take a look at what your email client does when
processing the message.

I don't understand how gpg-encrypted and signed mail will reduce spam in
this situation and it significantly reduces usability.

To be usable you'll need to have a good story for how to discover the
address at which you can communicate with a user.