We're making good progress on hole-punching, but it isn't available yet. Once complete, that should take some pressure/cost off the transit relay machine.
Note that the transit relay only sees ciphertext (for bulk data transfers). Even the mailbox server only sees ciphertext or SPAKE key-exchange messages. No server sees plaintext ever.
Note that the transit relay only sees ciphertext (for bulk data transfers). Even the mailbox server only sees ciphertext or SPAKE key-exchange messages. No server sees plaintext ever.