text: -- The table to answer the question: Was my email sent, when, any error, any warning?
  -- We don't store raw text here, just a hash.
  CREATE TABLE mailer_audit
  (
      id              character varying(26) NOT NULL PRIMARY KEY,
      account_id      character varying(26) NOT NULL,
      span_id         character varying(26) NOT NULL,
      template_id     character varying(26) NOT NULL,
      created_at      timestamp             NOT NULL,
      recipient_hash  character varying(32) NOT NULL,
      context_hash    character varying(32) NOT NULL,
      error_code      integer,
      error_message   character varying(255),
      warning_message character varying(255),
      FOREIGN KEY (account_id) REFERENCES mailer_account (id),
      FOREIGN KEY (template_id) REFERENCES mailer_template (id)
  );
  