-- Senders a mailbox has said it trusts.
--
-- Two things hang off one decision: mail from a trusted sender is not filed as
-- spam, and its remote images load without asking. Both used to be forgotten:
-- moving a message out of Junk taught nothing, so the next reply from the same
-- person went to Junk again, and the choice to show images lived in one
-- browser's storage.
CREATE TABLE trusted_senders (
    mailbox_id UUID NOT NULL REFERENCES mailboxes(id) ON DELETE CASCADE,
    -- Lowercased, so one person is one row however they spell their address.
    address    VARCHAR(320) NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    PRIMARY KEY (mailbox_id, address)
);