Compositions of proteins having free thiols, and methods of making and using such compositions, are described. The method of delivering wills and messages enables not only an invitor to efficiently and reliably leave behind a will and a message to one or more invitee but also the death of the invitor to be quickly determined by the invitee, thereby improving the reliability of the determination of death. As such, the aggregation server may increase a period of sending messages to the target message box based upon a delivery failure message therefrom, and thereafter decrease the period of sending messages to the target message box based upon a successful delivery of a message thereto. In the stowed position, the cam surface maintains the interference balls projecting outward from openings in the support base to secure the ball hitch into the towing vehicle.