However, letters work differently; they are [from: Alice's current geographical address to: Bob's current geographical address].
Keychat separates the receiving address and sending addresses from the ID, and the receiving address and sending addresses are also different. Keychat messages are [from: Alice's one-time sending address to: Bob's almost one-time receiving address]. This makes it difficult for outsiders and relay administrators to determine who is sending messages to whom.
(The new note has modified some expressions, making it clearer.)
quoting note1h84…gse4In practice, when we fill out an envelope, we don’t need to include the sender’s information; we only need to write the recipient’s address, and there’s no need to write the recipient’s name. As long as the recipient’s address is precise enough, the letter can be successfully delivered. Not needing to write the sender’s information is equivalent to being able to write any random address. note13pu…6q2c