Determining whether an exercise of constitutional executive power is a manifestation of the royal prerogative or merely a new excuse for executive excess, is notoriously difficult. The royal prerogative remains elusive, notwithstanding a millennium of its exercise. Often its use is viewed as falling on the fringes of government action—honours and awards, the exercise of mercy, or the movement of troops around the country. Other times it has been abridged by statute: either explicitly or implicitly. Yet, its breadth and depth remain potent within modern Australia. This chapter looks to address specifically the oft-referenced and historically well-used prerogative of reading the royal mail as a model for digital resilience. It does so to highlight the residual power that remains in section 61 of the Australian Constitution and to provide a useful case study on the fine line between valid prerogative evolution and invalid expansion of executive power unsanctioned by parliament.