In this paper, design and development of a mailbox server as thesoftware payload for TUUSAT-1, an experimental micro-satellite byTaiwan’s universities, and the ground station for operating the TUUSAT-1satellite are described. A commercial-on-the-shelf (COTS) amateurtransceiver is modified and re-designed to work as the communicationsubsystem, and the PACSAT protocol, a wireless communication protocolespecially suited for amateur satellite communication, is used in designingthe mail server software payload. Successful functional tests of theTUUSAT-1 by integrating and operating of the ground station show that theobjective of stored-and-forward mailbox server as a software payload forTUUSAT-1 is achieved, which exhibits the evidence that the idea ofsoftware payload fits the mission objective of lower communication rateand low cost of experimental satellite among Taiwan’s universities.