When users delete a message they're given a scary "this is permanent" message. It would be great if a Trash folder were implemented. Users could then delete without worry knowing their message could be recovered. The trash could either be kept forever (as SMS aren't big data-wise) and users can permanently delete individual messages, or a limit of x messages/x days/weeks old could be set to delete messages in Trash after that time. A first-time usage of the delete could show a small popup saying their message has been sent to the Trash and how to change settings for that.