Would it be too much to ask for IM protocols to support positive confirmation that a message has been receieved? It’s a two-way communication, so it shouldn’t be that hard. It wouldn’t even necessarily have to add much overhead or delay. After every X number of bytes receievd or Y minutes, each client could send an ACK message to the other with the IDs of the messages it has receieved and maybe a checksum. Messages that you type would initially be displayed in a “pending” color, and would only be changed to a “receieved” color once positive confirmation was received. This is not rocket science. With this simple feature, there would be no more tedious “are you receiving me?” exchanges.