Mark as unread, manage different folders & groups, batch actions (mark as read, unread, block, add to list, etc), and so on... Snooze would be great too, scheduled send as well.

Bonus points if everything is rendered correctly & I don't have to chase relays to actually find the DMs again. (Amethyst is great already, so please don't read this as a complaint, it's a brain dump and I started replying before I saw who I was replying to 😅)