In the last years, the study of kinetic fragility and its relationship with the glass structure in binary and mixed glass former phosphate glasses with potential applications [1] and [2] is getting a renewed interest, fostered in part because of the topological constraint theory [3], [4] and [5]. However, even though much progress has been achieved in this respect [6] and [7], there is still a lack of experimental data, which can substantiate the existing theories. In a recent work by Muñoz-Senovilla et al. [8], the viscosity and kinetic fragility of a series of metaphosphate glasses were analyzed in terms of the variation of molar volume and bond strength as well as of the possible arrangements in chains and rings of the phosphate building units. It was concluded that the medium-range order structure in the glasses could strongly influence not only the fragility, but also the activation energy for viscous flow above the glass transition temperature and the melt. Through this work, it was clear that the modifier induces a different intermediate order structure and thus a different behavior of the fragility and activation energy for viscous flow. In view of the important influence of the structural role of the constituting cations, Rodrigues et al. have also been able to predict the glass transition temperature in different alkali phosphate glasses by using a model that considers the coordination environment of the modifiers [9].