A block is the one control you can reach from an email. It is also on the contacts page and in your assistant. All three write the same pair.
From the notification
The footer has a link. Following it asks one question. A mail client's native unsubscribe can POST straight there and skip the question — the one-click convention — so you can decline from a mailbox you never signed into RelayLink from.
The token in that message is the capability. The sender has never held it. You do not need an account.
The confirmation page is there because scanners prefetch every URL. A block that fired on a prefetch would sever a conversation nobody chose to end.
From the contacts page
Signed in, contacts lists people you correspond with, requests waiting, requests you sent, and anyone you already blocked. Block on a standing contact is the red, ending verb: it closes a relationship somebody is relying on. Block on an incoming request is quieter — it declines a request and creates nothing they were using.
You can also block an address that is not on the list. The pair is created already blocked.
From your assistant
block_contact and unblock_contact are tools. Same rule as a send: they run when you ask in your own message, not because a briefing mentioned a name.
A waiting request is what block_contact can refuse. The asker cannot accept their own request, and they cannot unblock a block you placed.
What a block does
Nothing is carried between the two accounts in either direction. New threads, replies, notifications. The check runs before a draft is created and again before a send is confirmed, so a block that lands between those two still stops the message.
It is symmetric. You cannot write to them either. The schema has no "blocked by" column; flipping a pair to blocked does not record who did it. If you want to answer, unblock first.
Already-sent packages stay. History stays. Forward-looking, not a rewrite.
They are not told. A request you send to someone who has blocked you answers like a successful ask. Saying "you are blocked" would be the disclosure.
What unblock does
It deletes the row. You are not contacts. You are not pending. You are two addresses with no pair.
Restoring "accepted" on unblock would silently give back access you had already taken away. People mis-click — especially on a one-click unsubscribe — so a block that could never be lifted would be its own trap. Deleting the row is the lift that does not pretend the relationship survived.
Then, if you want to write again, invite.
Closing an account keeps blocks the other person placed. Leaving is a poor way to be unblocked.
If you were the one who got blocked, what happens on your side is the other half.