In general, in one aspect, one embodiment of the present disclosure features a message delivery method. The method includes the steps of receiving a message including delivery instruction and delivery information indicating a time at which the message is to be delivered to a communication device of a recipient; storing the message; and delivering the message to the recipient at a time indicated by the delivery information. Further, the delivery instruction and the delivery information are set by a sender of the message. Other embodiments are also provided.