The firehose UPDATE path was also running the newsletter claim/send logic. Combined with the fact that the idempotency row in publication_post_sends is only inserted when newsletters are enabled at upsert time, this meant that editing an old post after newsletters were turned on for the publication would mail the post out to subscribers retroactively. Gate the newsletter block on event_type === "create" so only firehose creates can fire sends. Metadata sync (indexed flag, bsky like counts, bridgy deletion) still runs on updates as before. Co-authored-by: Claude <noreply@anthropic.com>