Methods and systems are described for permitting a user to specify the criteria for determining the success or failure of the transmission of an instant message. A computer system first identifies the user specified criteria. When the server computer system receives an instant message, the computer system determines whether the user specified criteria have been met. If the criteria are met, the computer system returns a successful acknowledgement message to the user. Since the user sets the criteria by which success will be determined, the meaning of a successful acknowledgement message will be clear to the user.