Decentralized email with gateway to SMTP

[sanity]

• Inboxes stored in a secure decentralized way in the network
• Support PGP transparently to the user, consider: https://sequoia-pgp.org/
• Gateway to normal Internet email through freenet.org, potentially allocating usernames in exchange for a recurring donation to the project
• Could potentially generate donations up-front by allowing donors to reserve their usernames, and perhaps start using @freenet.org aliases immediately
• Direct freenet.org -> freenet.org emails will be direct within the P2P network
• https://docs.rs/samotop/0.13.0/samotop/