You can tell in a way if the person has received it or not, that is only if the computer is on or if it is off, if the computer is on and they have not got winpopup open there is no way of telling, with Windows NT it's fine because the NT Message system is always running. With regrads to receiveing messages in my prog i have an example of sending and receiveing winpopup messages, i need to tidy it up first though