Electron dephasing process is important and interesting in disordered conductors. In general three-dimensional(3D) disordered metals, the electron-electron(e-e) scattering is negligibly weak compared with the electron-phonon(eph) scattering. Thus, the theoretical prediction concerning the e-e scattering rate 1/τee as a function of temperature T in 3D disordered conductor has not been fully tested so far, though it was proposed four decades ago. In the frame of free-electron-like model, the e-ph relaxation r...