The mobility μ of electrons photoinjected into CH3NH2 vapor was measured with a drift time-of-flight apparatus. At room temperature the μ. values ranged from 1100 cm2/(V·s) at the lowest density (n = 6 × 1018 cm-3) to 70 cm2/(V·s) at the highest density (n = 8 × 1019 cm-3). The normalized mobility nμ drops with increasing density as for other polar fluids. We use the Ioffe-Regel criterion for the onset of strong scattering. A simple criterion for evaluating the strengths of the electron-molecule interaction (suggested by Warman) permits us to determine a relation between dipole moment and strong scattering, valid for all polar fluids studied to date. Some conjectures about electron localization are offered.