It can be helpful to know if a sended message reaches it's target anyway. With the ICQ Ignore Checker you can detect if you are ignored by a specific character or not. Besides a single check you can let check your whole contact list. An important requirement in any case is that the desired user is online (visible for you) and his / her contact list is saved at the server (most usual case). Normally this check is anonymous, so the checked contact will not notice it.