We report on the measurements of the spin–lattice relaxation time, T 1, of Mn 12O 12(O 2CCH 2Bu t ) 16(CH 3OH) 4 · CH 3OH, a truly axial symmetry Mn 12 single-molecule magnet (SMM), with the view to examining the role of point symmetry and lattice-solvate molecules in this Mn 12 SMM. The measurements were made over 0.390–1.8 K, on freshly prepared single crystals which afforded much higher spectral resolution than magnetically aligned powder. The measured T 1 is found to be thermally activated, and follows either a T 2 or exponential behavior over 0.390–0.7 K, in contrast to the temperature-independent behavior for Mn 12-acetate, where Jahn–Teller isomers are thought to be the origin of the temperature-independent nuclear relaxation mechanism.