@lyyn @cehteh we'll see what users report from their real-life situations, shall we? Deletion is never guaranteed to work, from no messenger. Message receival is also not guaranteed to work. Many messengers show a "tick" to signal the message is sent. But it might never arrive on any end device. Delta's FAQ also says about read-receipts: "a read-receipt does not mean that someone has really read, let alone understood your message". Reality is a mess :)